The sum of an infinite geometric series is given by a+ar+ar^2 where a is the first term and r is the common ratio.
The sum of the series can be represented by :
a / ( 1 - r) = 12
a = 12 ( 1- r ) (1)
So....note that the sum of the terms with odd powers of r can be represented by :
ar + ar^3 + ar^5 + ar^7 + ..... + ar^(2n - 1) = 5 (2)
And note that the sum of the terms with even powers of r can be represented by :
a + ar^2 + ar^4 + ar^6 + ar^8 + ..... + ar^(2n) = 7 (3)
Multiply (2) by r on both sides
ar^2 + ar^4 + ar^6 + ar^8 + ..... + ar^(2n ) = 5r (4)
Subtract (4) from (3)
a = 7 - 5r (5)
Sub (5) into (1)
7 - 5r = 12(1 - r)
7 - 5r = 12 - 12r
7r = 5 → r = 5/7
Check
a = 7 - 5(5/7) = 24/7
a / ( 1 - r) =
(24/7) / ( 1- 5/7) =
(24/7) / ( 2/7) =
24 / 2 =
12
To know more about infinite geometric series, visit: brainly.com/question/23602882
#SPJ4
For a certain city, the high temperatures (in degrees Celsius) are plotted against the number of days after the new year.
The high temperature is a linear function of the number of days after the new year.
How to define a linear function?The slope-intercept definition of a linear function is given as follows:
y = mx + b.
For which the parameters are given as follows:
m is the slope, representing the rate of change.b is the intercept, representing the value of y when x = 0.Three points on the graph are given as follows:
(1, -3), (3,1) and (10,15).
The slopes, calculated as the change in y divided by the change in x, for each of the intervals is given as follows:
(1, -3) to (3,1): m = 4/2 = 2.(1,-3) to (10, 15): m = 18/9 = 2.(3,1) to (10,15): m = 14/7 = 2.Due to the constant slopes, the relationship is in fact a linear function.
Missing InformationThe problem asks if the high temperature in this city a linear function of the number of days after the new year.
More can be learned about linear functions at https://brainly.com/question/24808124
#SPJ1
Page 1:
a. If two points on a line are A(-5, 7) and B(-2, 1), the rise is
so the slope of the line is
b. If two points on a line are A(10, -3) and B(12, 9), the rise is
run is
the run is
so the slope of the line is
c. If two points on a line are A(4, 6) and B(8,-8), the rise is
run is
Page 2:
so the slope of the line is
a. In the point-slope form of a line.
mix
the clon
and the
, and
and the
a) If two points on a line are A(-5,7) and B(-2,1), the rise -6, the run is of 3, and then the slope is of -2.
b) If two points on a line are A(10,-3) and B(12,9), the rise 12, the run is of 2, and then the slope is of 6.
c) If two points on a line are A(4,6) and B(8,-8), the rise -14, the run is of 4, and then the slope is of -3.5.
How to calculate the slope a linear function?The slope-intercept definition of a linear function is given as follows:
y = mx + b.
For which the parameters are given as follows:
m is the slope, representing the rate of change.b is the intercept, representing the value of y when x = 0.As the slope represents the rate of change of the output relative to the input, it is calculated as the change in the output y divided by the change in the input x, that is, the rise divided by the run.
More can be learned about linear functions at https://brainly.com/question/24808124
#SPJ1
-8 + n/2 = -13
Please help me I’m begging we just started to learn this today
Answer:
-10
Step-by-step explanation:
-8 + n/2 = -13
n/2 = -13 + 8
n/2 = -5
n = -5 * 2
n = -10
Hope it helps!
I NEED HELP ON BOTH SIDES ASAP!!!
The solution of the graph are x=1 and y=11.
What is Slope of Line?The slope of the line is the ratio of the rise to the run, or rise divided by the run. It describes the steepness of line in the coordinate plane.
The slope intercept form of a line is y=mx+b, where m is slope and b is the y intercept.
The slope of line passing through two points (x₁, y₁) and (x₂, y₂) is
m=y₂-y₁/x₂-x₁
In the first graph the one line is passing through points (-1, -3) and (0,4)
m=4+3/0+1=7
4=7(0)+b
b=4
y=7x+4..(1)
Now other line passing through points (-4, 0) and (0, -4)
m=-4/4=-1
0=-1(-4)+b
b=-4
y=-x-4..(2)
-x-4=7x+4
Take all the variables on one side.
-x-7x=8
-8x=8
x=1
Now let us find y value
y=7+4=11
Hence, the solution of the graph are x=1 and y=11.
To learn more on slope of line click:
https://brainly.com/question/14511992
#SPJ1
michael is 3 33 times as old as brandon. 18 1818 years ago, michael was 9 99 times as old as brandon. how old is michael now?
Michael is 3 33 times as old as brandon. 18 1818 years ago, michael was 9 99 times as old as brandon so michael is 272454 years old.
Since we have given that
Michael is 3 times as old as Brandon .
Let the age of Brandon be 'x'.
Let the age of Michael be 333x
According to question, 181818 years ago, Michael was 999 times as old as Brandon.
181818 years ago,
Age of Brandon was x-181818
Age of Michael was 333x-181818
So, our equation becomes,
999( x- 181818) = 333x - 181818
999x - 181636182 = 333x - 181818
666x = 181454364
x = 272454
Hence, Age of Brandon is 272454 years.
Learn more about Age problems:
https://brainly.com/question/2785518
#SPJ4
How many pounds are in 5 kilograms?
StartFraction 6 kilograms Over 13.23 pounds EndFraction = StartFraction 5 kilograms Over question mark pounds EndFraction
11.025 pounds
15.435 pounds
15.876 pounds
24.255 pounds
Answer:
A. 11.025
Step-by-step explanation:
1 Kilogram equals exactly 2.20462 pounds.
2.20462 multiplied by 5 is 11.025
I want to know how can I write this
in scientific notation
Step-by-step explanation:
(3*10^9)(2.3*10^7)
=
[tex]6.9 \times {10}^{16 \\} [/tex]
PLS HELP
The sum of two numbers is 57 . The larger number is 9 more than the smaller number. What are the numbers?
Larger number:
Smaller Number:
EXPLAIN WILL MAKE YOU THE BRAINLIEST
Answer:
Larger number will be 33
Smaller number will be 24
Step-by-step explanation:
So the easiest way to go about this is to divide the each of numbers by two
57/2 = 28.5
9/2 = 4.5
so now we have two 28.5's we will add 4.5 to one and subtract 4.5 from one
28.5 + 4.5 = 33
28.5 - 4.5 = 24
Proof:
33 + 24 = 57
33 - 24 = 9
Answer:
Smaller number = 24, Larger number = 33
Step-by-step explanation:
x + (x+9) = 57 Set up equation x is the smallest number and (x+9) is he larger number
2x+9 = 57
2x = 48
x = 24
Smaller number = 24, Larger number = 33
solve 5x + 30 > - 15
x>-9 is the solution of the inequality 5x + 30 > - 15
What is Inequality?a relationship between two expressions or values that are not equal to each other is called 'inequality.
The given inequality is 5x+30>-15
Five times of x plus thirty greater than minus fifteen.
Subtract 30 on both sides
5x>-45
Divide both sides by 5
x>-9
Hence, x>-9 is the solution of the inequality 5x + 30 > - 15
To learn more on Inequality click:
https://brainly.com/question/28823603
#SPJ1
-10v³ +50v² +40v
(Factor)
Answer:
-10v([tex]v^{2}[/tex] - 5v - 4)
Step-by-step explanation:
First, we have to find the GCF
The GCF is: -10v
We factor the GCF outside, and what is left we put in the ( )
-10v([tex]v^{2}[/tex] - 5v - 4)
2. The equation and the graph represent two functions. Use the equation y = 4 and the graph to answer the questions.
a) When x = 4, the function y = 4 has the greater numeric value.
b) The two equations have the same value for x = 6.
How to define the linear function?The slope-intercept definition of a linear function is given as follows:
y = mx + b.
For which the parameters are given as follows:
m is the slope, representing the rate of change.b is the intercept, representing the value of y when x = 0.From graph, when x = 0, y = 1, hence the intercept b is given as follows:
b = 1.
When x increases by two, y increases by one, hence the slope m is given as follows:
m = 1/2
m = 0.5.
Meaning that the function is given as follows:
y = 0.5x + 1.
When x = 4, the value is given as follows:
y = 0.5(4) + 1
y = 3 < 4.
The two functions will have the same value when:
0.5x + 1 = 4
0.5x = 3
x = 3/0.5
x = 6.
More can be learned about linear functions at https://brainly.com/question/24808124
#SPJ1
A right cone has a base with diameter 6 units. The volume of the
cone is 72π cubic units. What is the length of a segment drawn
from the apex to the edge of the circular base? Round to the
nearest tenth. This is a multi-step problem so DO NOT ROUND
UNTIL YOU GET TO YOUR FINAL ANSWER!!
HINT: DRAW A DIAGRAM!!
The segment drawn from the apex to the edge of the circular
base is____units.
The slant height of the right cone is 24.2 units, rounded to the nearest tenth.
The Pythagorean Theorem: What is it?A right triangle's hypotenuse, or side opposite the right angle, has a square length that, according to the Pythagorean theorem, is equal to the sum of the squares of the lengths of the other two sides.
The Pythagorean Theorem can be used to determine the slant height of a right cone. The circular base's radius is equal to its diameter times half, or 6/2 = 3 units.
The volume of the cone can be found using the formula:
V = (π/3)r²h
Where r is the radius, and h is the height of the cone. Plugging in the given values, we have:
72π = (π/3)r²h
72π = (π/3)3²h
72π = (π/3)9h
72π = 3πh
24 = h
Using the Pythagorean Theorem, we can find the slant height as follows:
c² = a² + b²
Where a and b are the height and radius of the cone, and c is the slant height. Plugging in the values we have:
c² = 24² + 3²
c² = 576 + 9
c² = 585
c = 24.2
Hence, the slant height of the right cone is 24.2 units, rounded to the nearest tenth.
Learn more about Pythagorean Theorem here:
brainly.com/question/343682
#SPJ1
what is the rest of this table please help i dont understand
The table can be completed including the Elapsed Time and Average Speed, with the assumption that the length of the entire track is 1 meters as follows;
[tex]{}[/tex] Time (Initial)(s) (Final)(s) Elapsed(s) Average Speed (m/s
1st 1/4 of the Track [tex]{}[/tex] 0.74 2.07 1.33 0.19
2nd 1/4 of the Track 1.40 [tex]{}[/tex] 1.09 0.31 0.81
3rd 1/4 of the Track[tex]{}[/tex] 1.60 0.95 0.65 0.38
Final 1/4 of the Track [tex]{}[/tex]1.88 0.81 1.07 0.23
What is the average speed of an object?Average speed is the ratio of the distance an object travels to the duration the object takes to travel.
The data in the table can be completed by plugging in the values in the following equations.
Elapsed Time = Time (Final) - Time (initial)
Average Speed = Distance traveled in the time interval/(Elapsed Time)
The values of the 1st 1/4 of the track, indicates that we get;
Elapsed Time = 2.07 - 0.74 = 1.33
The elapsed time is 1.33 seconds
Average Speed = (1/4)/1.33 = 25/133 ≈ 0.19
The Average Speed is about 0.19 m/s
The values for the 2nd 1/4 of the Track, we get;
Elapsed Time = 1.40 - 1.09 = 0.31
Elapsed Time = 0.31 s
Average Speed = (1/4)/(0.31) = 25/31 ≈ 0.81
The Average Speed for the 2nd 1/4 is about 0.81 m/s
The 3rd 1/4 of the Track indicates;
Elapsed Time = 1.60 - 0.95 = 0.65
The Elapsed Time = 0.65 s
Average Speed = (1/4)/0.65 = 5/13 ≈ 0,38
The Average Speed ≈ 0.38 m/s
The Final 1/4 of the Track indicates;
Elapsed Time = 1.88 - 0.81 = 1.07
The Elapsed Time is 1.07 s
The Average Speed = (1/4)/1.07 = 25/107 ≈ 0.23
The Average Speed for the Final 1/4 of the Track is about 0.23 m/s
The table can be completed with the above calculated values
Learn more about average speed here: https://brainly.com/question/17036010
#SPJ1
Help plis es para hoy
The diameter of the cone is 18 in.
What is a cone?It is a shape of a Christmas tree where there is a base of radius r and a top point called the apex.
The volume of a cone is
We have,
Volume = 1040 in³
Height = 12 in
The volume of a cone is (1/3)πr²h.
So,
1040 = (1/3)πr²h
3 x 1040 = πr² x 12
3120/12 = πr²
260 = 3.14 x r²
260/3.14 = r²
r² = 82.80
r = √(82.80)
r = 9.099
r = 9 in
Now,
Diameter = 2r
So,
= 2 x 9
= 18 in
Thus,
The diameter is 18 in.
Learn more about cones here:
https://brainly.com/question/13798146
#SPJ1
EH is the perpendicular bisector of DF. Find the indicated measure.
Find EF
Find FG
Find DF
The values of the indicated measures are:
i. EF = 44 units
ii. FG = 36 units
iii. DF = 62 units
What is a perpendicular bisector?A straight line that divides a given line into two equal parts and which is at right angle is called a perpendicular bisector of a line segment.
So that to determine the values of indicated measures, we have:
FE = ED
7x + 9 = 9x - 1
collect like terms
1 + 9 = 9x - 7x
10 = 2x
x = 10/ 2
x = 5
Also,
FG = GD
7y + 8 = 10y - 4
collect like terms,
4 + 8 = 10y - 7y
12 = 3y
y = 12/ 3
y = 4
Therefore;
i. EF = 7x + 9
= 7(5) + 9
= 35 + 9
EF = 44 units
ii. FG = 7y + 8
= 7(4) + 8
= 28 + 8
FG = 36 units
iii. DF = 2(3x + 4y)
= 2(3*5 + 4*4)
= 2(15 + 16)
= 2(31)
DF = 62 units
Learn more about perpendicular bisector at https://brainly.com/question/929137
#SPJ1
suppose that an usher randomly assigns the seats to the 7 people. find the probability that the three friends are next to each other.
The probability that the three friends are seated next to each other is 1/420
The total number of ways to seat the 7 people is 7! To find the number of ways to seat the three friends next to each other, we need to consider the number of ways to seat the other 4 people around them. So the number of favorable outcomes is 4!
The probability that the three friends are next to each other is then given by the ratio of the number of favorable outcomes to the total number of outcomes: (4!)/(7!) = 4!/5040 = 1/420.
So the probability that the three friends are seated next to each other is 1/420.
To learn more about probability, refer:-
https://brainly.com/question/9793303
#SPJ4
What is the measure of angle
XNM?
O 40
O 80
O 90
O 160
Check the picture below.
Example 1) Suppose it is known that the height of all Canadians follows a normal distribution
with a mean of 160 cm and a standard deviation of 7 cm. What is the corresponding z score to the probability that the average height of Canadians is less than 157 cm?
The probability that the average height of Canadians is less than 157 cm is 0.337.
What is z-score?The relationship between a value and a set of values' mean is described by the statistical measurement known as the Z-score. Standard deviations from the mean are used to measure Z-score. A Z-score of zero means the data point's score is the same as the mean score. A value that is one standard deviation from the mean would have a Z-score of 1.0. Z-scores can be either positive or negative, with a positive number signifying a score above the mean and a negative value signifying a score below the mean.
Given that the standard deviation = 7cm and the mean = 160cm.
The z -score is given as:
z = x - mean / SD
z = 157 - 160/ 7
z = -3/7
z = - 0. 428
z = 0.337
P (X < 157) = P (z < -0.428)
P(X < 157) = 0.337
Hence, the probability that the average height of Canadians is less than 157 cm is 0.337.
Learn more about normal distribution here:
https://brainly.com/question/13104625
#SPJ1
Help me really fast please I need to go to the store and I need to have the answer
Answer: B. 2 quarts
Step-by-step explanation: 16 divided by 8 is 2 so you multiply 2 by 1 and you get 2. :)
A group of students was surveyed in a middle school class. They were asked how many hours they work on math homework each week. The results from the survey were recorded.
Number of Hours Total Number of Students
0 1
1 8
2 2
3 5
4 9
5 7
6 3
Determine the probability that a student studied for exactly 1 hour. Round to the nearest hundredth.
0.03
0.23
0.30
0.77
Based on the data provided, the probability that one student studied for exactly one hour is 0.22.
What is the probability in this case?When it comes to calculating the probability, we need to identify the frequency of a specific outcome (the probability a student studied for one hour) and compare it to the total outcome (total of students) as follows:
Total of students who studied for one hour: 8
Total of students: 1+8+2+5+9+7+3 = 35
Total of students who studied for one hour / total students
8/35 = 0.228 which can be rounded as 0.23 or 23% if expressed as a percentage.
Learn more about probabilities in https://brainly.com/question/30034780
#SPJ1
explain or show that we can approximate the area covered by mold in 8 weeks by multiplying a(7) by 1.01
The formula a(7) * 1.01 represents an exponential growth model, where a(7) is the area covered by mold at week 7, and 1.01 represents a growth rate of 1% per week.
The exponential growth model is represented by the formula a(7) * 1.01, where a(7) is the area covered by mould at week 7, and 1.01 indicates a weekly growth rate of 1%.
By multiplying the area at week 7 by 1.01, we can approximate the area covered by mold at week 8.
However, it's important to note that this model assumes that the growth rate remains constant and does not account for any limiting factors such as availability of food or changes in environmental conditions.
Additionally, this model may not accurately represent the actual growth of mold, as mold growth can be complex and affected by many variables.
For more questions on exponential growth model
https://brainly.com/question/13617239
#SPJ4
what are some advantages of online surveys? multiple select question. they are generally readily available to survey responders. the data can be downloaded automatically into a spreadsheet. they deliver more accurate results than other types of surveys. the surveys can reach a very large number of respondents.
A, B, and D are some advantages of online surveys.
The advantages of online surveys are:
They are generally readily available to survey responders, as respondents can access the survey from anywhere with an internet connection.The surveys can reach a very large number of respondents, which can lead to a more representative sample.The data can be downloaded automatically into a spreadsheet, which makes it easier to analyze and process the data.They deliver more accurate results than other types of surveys, as online surveys can enforce skip patterns and provide immediate feedback to respondents.Online surveys are often less expensive than traditional surveys, as they do not require printing, postage, or interviewer time.To learn more about the online surveys, refer:-
https://brainly.com/question/28268462
#SPJ4
what is the third-life of woosterium-21? that is, find the time it takes a sample of woosterium-21 to decay to 1 / 3 1/3 of its original amount. round your answer to three decimal places. (enter only a number. do not include units.)
The time it takes a 100g sample of woosterium-21 to decay to 1/3rd of its original amount is 3.002 hours.
The initial amount of woosterium-21 (Ni) that is provided is 100g
The half life of woosterium-21 (t1/2) is given as 3 hours
The final time (t) is provided as 10 hours
The equation for half life is given by the equation:
Nt = Ni * (1/2)^(t/t₁/₂)
Where, Nt = the final amount of woosterium-21 after 10 hours.
Therefore, Nt = 100 * (1/2)^(10/3) = 100 * 0.5^3.33 = 100 * 0.09944 = 9.944g
Let third life of woosterium-21 be t₁/₃
Substituting values in equation Nt = Ni * (1/2)^(t/t₁/₂)
9.944 = 100 * (1/2)^(10/t₁/₃)
0.9944 = (1/2)^(10/t₁/₃)
Taking log on both sides,
log 0.9944 = 10/(t₁/₃) log 0.5
-1.0026 = 10/(t₁/₃) * (-0.301)
1.0026 = 3.01/(t₁/₃)
t₁/₃ = 3.002 hours
Therefore, the third life of woosterium-21 was found to be 3.002 hours.
Learn more about half life here brainly.com/question/16387602
#SPJ4
Complete Question: Suppose that Woosterium-21 is a radioactive substance that has a half-life of 3 hours. (Woosterium-21 does not, as far as I know, exist in real life.) Suppose the initial amount of Woosterium-21 is 100 mg. How much Woosterium-21 remains after 10 hours? Round your answer to three decimal places. (Enter only a number. Do not include units.) |What is the third-life of Woosterium-21? That is, find the time it takes a sample of Woosterium-21 to decay to 1/3 of its original amount. Round your answer to three decimal places. (Enter only a number. Do not include units.
Slope of the line perpendicular to the line
The slope of the perpendicular line is the inverse reciprocal of the line on which the line is perpendicular.
What is a slope?A line's slope is determined by how its y coordinate changes in relation to how its x coordinate changes. y and x are the net changes in the y and x coordinates, respectively. Therefore, m = y/x can be used to express the change in the y coordinate with regard to the change in the x coordinate.
The slope of two parallel lines is such that the slope of one line is equal to the reciprocal of the negative slope of the other. The relationship between the slope of perpendicular lines can be represented by the formula m1 if the slopes of the two perpendicular lines are m1, m2.
To know more about slope follow
https://brainly.com/question/20719015
#SPJ1
In a poll, students were asked to choose which of six colors was their favorite. The circle graph shows how the students answered. If 14,000 students participated in the poll, how many chose Green?
Purple
6%
Pink
10%
Red
12%
Blue
21%
Green
39%
Orange
12%
Answer:
Step-by-step explanation:
you get 5000 and divide 21and it equals 238 people
the denominator of a fraction is 9 more than the numerator. if the numerator is decreased by 3 and th denominator is increased by 3, the value od fraction is 1/4 . what is the original fraction ?
The original fraction is 3/12.
The original fraction is 5/12. This can be determined by solving the equation provided. The equation states that the denominator of a fraction is 9 more than the numerator and that if the numerator is decreased by 3 and the denominator is increased by 3, the value of the fraction is 1/4. To solve, we can set up an equation, where x is the numerator and (x+9) is the denominator.
Let the original fraction be x/y
According to the given information,
y = x + 9
After making the changes,
x - 3 = 1
and
y + 3 = 4
Now, substituting the value of y from the first equation in the second equation,
x - 3 = 1
and
x + 6 = 4
Solving the above equations,
x = 3
and
y = 12
Therefore, the original fraction is 3/12.
Learn more about fraction here:
https://brainly.com/question/1301963
#SPJ4
you have an ordinary deck of 52 well-shuffled cards. you remove the cards one at a time until you get an ace. let the random variable x denote the number of cards removed. what is the probability mass function of x? make sure to specify where x can take values. recall that there are four aces in a standard 52-card deck.
The probability mass function of x is p(x) = 4/52 * (48/51)^(x-1) * (1/51)^(52-x) for x = 1, 2, ..., 52.
How to determine the probability mass functionFrom the question, we have the following parameters that can be used in our computation:
x denote the number of cards removed
This means that
x = 1, 2, ..., 52
The probability of selecting an ace is
P(Ace) = 4/52
This means that
P(Ace') = 48/51 ----- the card is selected without replacement
When x Aces are selected, the remaining cards is 52 - x
Using the above as a guide, we have the following:
PMF = 4/52 * (48/51)^(x-1) * (1/51)^(52-x) for x = 1, 2, ..., 52.
Read more about probability at
https://brainly.com/question/251701
#SPJ1
and Bill collect coins. Karen has x coins. Bill has 6 coins fewer than two times the number of coins Karen has. Write and simplify an expression for the total number of coins Karen and Bill have.
Answer:
3x - 6
Step-by-step explanation:
Let's call the number of coins Karen has "x".
According to the information given, Bill has 6 coins fewer than two times the number of coins Karen has, so we can write the following expression for the number of coins Bill has:
Bill: 2x - 6
To find the total number of coins Karen and Bill have, we simply add the number of coins each person has:
Karen + Bill: x + (2x - 6) = 3x - 6
So the total number of coins Karen and Bill have is 3x - 6.
Answer: the total amount of coins Bill and Karen have can be found with the following equation: 3x-6
Step-by-step explanation:
Karen has x coins
Bill's coins are twice the x, so 2x, and he has 6 fewer than that.
The equation becomes x+2x-6 which can be simplified to 3x-6.
In the triangle below, angle BCA is obtuse.
Calculate angle BCA to 1 d.p
Answer:
56.27⁰
Step-by-step explanation:
a/sinA =b/sinB
35/sin 50⁰ = 38/sin B
cross multiply
35sinB = 38sin50⁰
sin B=29.1096/35
sinB=0.8317 find the inverse sine
angle BCA= 56.27⁰
g suppose 50 students took an exam and the average score was 70 with a standard deviation of 10. use 68-95-99.7 rule for questions dealing with normal distribution. if the distribution of scores is perfectly normal, how many students would you expect to get an a? (a score between 90 and 100) round up to nearest whole number.
Only one student is expected receive an A for the exam.
The 68-95-99.7 rule states that for a normal distribution, 68% of the data falls within one standard deviation of the mean, 95% of the data falls within two standard deviations of the mean, and 99.7% of the data falls within three standard deviations of the mean.
In this case, the mean is 70 and the standard deviation is 10, so the range of scores that would be considered an "A" would be between 90 and 100.
We can calculate the number of standard deviations from the mean that the range 90 to 100 covers and use the 68-95-99.7 rule to estimate the percentage of students who would receive an "A".
For a score of 90, the number of standard deviations from the mean is (90 - 70) / 10 = 2.
For a score of 100, the number of standard deviations from the mean is (100 - 70) / 10 = 3.
So, the range of scores between 50 and 90 covers two standard deviations from the mean and between 40 and 100 covers three standard deviations from the mean. According to the 68-95-99.7 rule, 99.7% of the data falls within three standard deviations of the mean and 95% of the data falls within two standard deviations of the mean, so we would expect about (99.7% - 95%)/2 = 2.35% of the students to receive an "A".
With 50 students, we would expect approximately 50 * 0.0235 = 1.175 ≈ ` student to receive an "A". We can round up to the nearest whole number to get an estimate of 50 students.
To know more on 68-95-99.7 rule
https://brainly.com/question/29255280
#SPJ4