2. In your own words, explain HOW to find the standard deviation of this data set. (20 points) 3. What does the standard deviation tell you about this data? (20 points) I NEEDDDDD THISSSSSS PLSSSSSSSSSSSSSSSS
Answers
Answer:
[tex]\sigma = 11.28[/tex] --- Standard deviation
Step-by-step explanation:
Given
See attachment for graph
Solving (a): Explain how the standard deviation is calculated.
Start by calculating the mean
To do this, we divide the sum of the products of grade and number of students by the total number of students;
i.e.
[tex]\bar x = \frac{\sum fx}{\sum f}[/tex]
So, we have:
[tex]\bar x = \frac{50 * 1 + 57 * 2 + 60 * 4 + 65 * 3 +72 *3 + 75 * 12 + 77 * 10 + 81 * 6 + 83 * 6 + 88 * 9 + 90 * 12 + 92 * 12 +95 * 2 + 99 * 4 + 100 * 5}{1 + 2 + 4 + 3 +3 + 12 + 10 + 6 + 6 + 9 + 12 + 12 +2 + 4 + 5}[/tex]
[tex]\bar x = \frac{7531}{91}[/tex]
[tex]\bar x = 82.76[/tex]
Next, calculate the variance using the following formula:
[tex]\sigma^2 = \frac{\sum f(x - \bar x)^2}{\sum f}[/tex]
i.e subtract the mean from each dataset; take the squares; add up the squares; then divide the sum by the number of dataset
So, we have:
[tex]\sigma^2 = \frac{1 * (50 - 82.76)^2 +...................+ 5 * (100 - 82.76)^2}{91}[/tex]
[tex]\sigma^2 = \frac{11580.6816}{91}[/tex]
[tex]\sigma^2 = 127.26[/tex]
Lastly, take the square root of the variance to get the standard deviation
[tex]\sigma = \sqrt{\sigma^2}[/tex]
[tex]\sigma = \sqrt{127.26}[/tex]
[tex]\sigma = 11.28[/tex] --- approximated
Hence, the standard deviation is approximately 11.28
Considering the calculated mean (i.e. 82.76), the standard deviation (i.e. 11.28) is small and this means that the grade of the students are close to the average grade.
Related Questions
Divide Rs.45000 among 2 students Mina and Rita in the ratio of marks they got 40 and 50 respectively
Answers
Let
Money share of Mina=40xMoney shae of Rita=50xATQ
[tex]\\ \qquad\quad\sf{:}\twoheadrightarrow 40x+50x=45000[/tex]
[tex]\\ \qquad\quad\sf{:}\twoheadrightarrow 90x=45000[/tex]
[tex]\\ \qquad\quad\sf{:}\twoheadrightarrow x=\dfrac{45000}{90}[/tex]
[tex]\\ \qquad\quad\sf{:}\twoheadrightarrow x=500[/tex]
Now
[tex]\\ \qquad\quad\sf{:}\twoheadrightarrow Rita=50x=50(500)=25000[/tex]
[tex]\\ \qquad\quad\sf{:}\twoheadrightarrow Mina=40x=40(500)=20000[/tex]
f(x) = 2[tex]x^{2}[/tex]+ x − 4 for x ∈R, a ≤ x ≤ a+3. If the range of the function f is −2 ≤ f(x) ≤ 16, find the possible values of a.
Answers
Answer:
No answer is possible
Step-by-step explanation:
First, we can identify what the parabola looks like.
A parabola of form ax²+bx+c opens upward if a > 0 and downward if a < 0. The a is what the x² is multiplied by, and in this case, it is positive 2. Therefore, this parabola opens upward.
Next, the vertex of a parabola is equal to -b/(2a). Here, b (what x is multiplied by) is 1 and a =2, so -b/(2a) = -1/4 = -0.25.
This means that the parabola opens upward, and is going down until it reaches the vertex of x=-0.25 and up after that point. Graphing the function confirms this.
Given these, we can then solve for when the endpoints of the interval are reached and go from there.
The first endpoint in -2 ≤ f(x) ≤ 16 is f(x) = 2. Therefore, we can solve for f(x)=-2 by saying
2x²+x-4 = -2
add 2 to both sides to put everything on one side into a quadratic formula
2x²+x-2 = 0
To factor this, we first can identify, in ax²+bx+c, that a=2, b=1, and c=-2. We must find two values that add up to b=1 and multiply to c*a = -2 * 2 = -4. As (2,-2), (4,-1), and (-1,4) are the only integer values that multiply to -4, this will not work. We must apply the quadratic formula, so
x= (-b ± √(b²-4ac))/(2a)
x = (-1 ± √(1-(-4*2*2)))/(2*2)
= (-1 ± √(1+16))/4
= (-1 ± √17) / 4
when f(x) = -2
Next, we can solve for when f(x) = 16
2x²+x-4 = 16
subtract 16 from both sides to make this a quadratic equation
2x²+x-20 = 0
To factor, we must find two values that multiply to -40 and add up to 1. Nothing seems to work here in terms of whole numbers, so we can apply the quadratic formula, so
x = (-1 ± √(1-(-20*2*4)))/(2*2)
= (-1 ± √(1+160))/4
= (-1 ± √161)/4
Our two values of f(x) = -2 are (-1 ± √17) / 4 and our two values of f(x) = 16 are (-1 ± √161)/4 . Our vertex is at x=-0.25, so all values less than that are going down and all values greater than that are going up. We can notice that
(-1 - √17)/4 ≈ -1.3 and (-1-√161)/4 ≈ -3.4 are less than that value, while (-1+√17)/4 ≈ 0.8 and (-1+√161)/4 ≈ 2.9 are greater than that value. This means that when −2 ≤ f(x) ≤ 16 , we have two ranges -- from -3.4 to -1.3 and from 0.8 to 2.9 . Between -1.3 and 0.8, the function goes down then up, with all values less than f(x)=-2. Below -3.4 and above 2.9, all values are greater than f(x) = 16. One thing we can notice is that both ranges have a difference of approximately 2.1 between its high and low x values. The question asks for a value of a where a ≤ x ≤ a+3. As the difference between the high and low values are only 2.1, it would be impossible to have a range of greater than that.
Here are the numbers of children in 11 elementary school classes.
18, 18, 17, 18, 19, 20, 17, 17, 17, 18, 20
Find the modes of this data set.
Answers
Hey there!
Mode is basically the number(s) in a data plot you see MORE THAN once
• 18 appeared four times (this could be a possible answer)
• 17 appeared four times (this could be a possible answer)
• 19 appeared one time (this can’t be your answer)
• 20 appeared two times (this could be a possible answer)
Possible answers: 17,18, & 20
Since 17 & 18 appeared the MOST in the data plot those numbers could be your mode in your given data plot
Answer: 17 & 18
Good luck on your assignment and enjoy your day!
~Amphitrite1040:)
three consecutive even numbers add up to 105 determine the product of the three numbers
Answers
Answer:
34 + 35 + 36 = 105
Step-by-step explanation:
khan academy
help:,)
Answers
Answer:
5
Step-by-step explanation:
It is 5 because you just have to count by using a jumping math tectechnique.
help please! how do I calculate the coordinates of point a so that at is an altitude?
Answers
Part (a)
Since we want segment AT to be an altitude, this means that point A is somewhere on segment RI such that angle TAI is 90 degrees. In other words, segments AT and RI are perpendicular. Check out the diagram below.
We'll need to find the slope of line RI, so we'll need the slope formula
R = (x1,y1) = (-2,-2)
I = (x2,y2) = (4,1)
m = slope of line RI
m = (y2-y1)/(x2-x1)
m = (1-(-2))/(4-(-2))
m = (1+2)/(4+2)
m = 3/6
m = 1/2
m = 0.5
The slope of line RI is 1/2 or 0.5
Now let's use point R(-2,-2) along with that slope we just found to find the equation of line RI.
Turn to point slope form
y - y1 = m(x - x1)
y - (-2) = 0.5(x -(-2))
y + 2 = 0.5(x + 2)
y + 2 = 0.5x + 1
y = 0.5x + 1 - 2
y = 0.5x - 1
This is the equation of line RI. We'll use it later.
----------
We found that the slope of line RI was 1/2.
The negative reciprocal involves us flipping the fraction and flipping the sign to get -2/1 or simply -2.
The perpendicular slope is -2. This is the slope of altitude AT.
We want line AT to go through T(-2,4), so we'll use this point along with the perpendicular slope we just found to calculate the equation of line AT.
We'll turn to the point slope form
y - y1 = m(x - x1)
y - 4 = -2(x - (-2))
y - 4 = -2(x + 2)
y - 4 = -2x - 4
y = -2x - 4 + 4
y = -2x
The equation of the line that goes through points A and T is y = -2x.
----------
To summarize so far, we have these two equations
y = 0.5x - 1 .... equation of line RIy = -2x .... equation of line ATApply substitution to solve for (x,y) to find the intersection point. This will determine where point A is located.
y = 0.5x - 1
-2x = 0.5x - 1
-2x-0.5x = -1
-2.5x = -1
x = -1/(-2.5)
x = 0.4
Then we can determine y like so
y = -2x
y = -2(0.4)
y = -0.8
Therefore, point A is located at (0.4, -0.8). Both coordinate values are exact. In fraction form, we can say that the point is (2/5, -4/5), but I find decimals easier to work with in this instance.
Answer: (0.4, -0.8)===============================================================
Part (b)
To find the length of segment AT, we can find the distance from A to T. As you can probably guess, we'll use the distance formula.
A = (x1,y1) = (0.4, -0.8) ... found back in part (a)
T = (x2,y2) = (-2, 4) ... given
[tex]d = \sqrt{ (x_2-x_1)^2+(y_2-y_1)^2 }\\\\d = \sqrt{ (-2-0.4)^2+(4 - (-0.8))^2 }\\\\d = \sqrt{ (-2-0.4)^2+(4 + 0.8)^2 }\\\\d = \sqrt{ (-2.4)^2+(4.8)^2 }\\\\d = \sqrt{ 5.76+23.04 }\\\\d = \sqrt{ 28.8 }\\\\d \approx 5.36656\\\\d \approx 5.37\\\\[/tex]
The distance from point A to point T is approximately 5.37 units. This means that segment AT is roughly 5.37 units long.
Answer: 5.37 unitsHelp find the equivalent fraction with the correct steps please !
-2/5 x 6/-1 ÷ 5/-2
What’s the equivalent fraction ? Please help! Tysm (:
Answers
Answer:
: = ÷
[tex]\frac{-2}{5}*\frac{6}{-1} : \frac{5}{-2} = \frac{-12}{-5} : \frac{5}{-2} = \frac{12}{5}*\frac{-2}{5}=\frac{-24}{25}[/tex]
An equivalent fraction is -24 over 25.
Write an equation in slope-intercept form for the line with slope 3/5 and y-intercept -1.
Answers
Answer:
y=3/5x-1
Step-by-step explanation:
Help me with this pls IM FAILING PYTHAGOREAN THEOREM
Answers
Answer: 33
Work Shown:
Apply the pythagorean theorem to get
[tex]a^2 + b^2 = c^2\\\\x^2 + 44^2 = 55^2\\\\x^2 + 1936 = 3025\\\\x^2 = 3025 - 1936\\\\x^2 = 1089\\\\x = 33[/tex]
What should the equations look like for each number? 17-20
Answers
Answer:
See below.
Step-by-step explanation:
17.)
[tex]x+100+120+100=360\\x+320=360\\x=40[/tex]
18.)
[tex]x+150+77+48=360\\x+275=360\\x=85[/tex]
19.)
[tex]x+122+92+76=360\\x+290=360\\x=70[/tex]
20.)
[tex]x+115+85+60=360\\x+260=360\\x=100[/tex]
4.
If you took a horizontal slice out of the three-dimensional shape, what two-
dimensional shape would you have?
1) rectangle
2) circle
3) square
4) triangle
Answers
Answer:
Square
Step-by-step explanation:
It got 4 sides like square and its form is looking like a square.
Evaluate the expression when x=-6.
x² + 5x-2
Answers
Answer:
Step-by-step explanation:
Hello!
x² + 5x-2
6² + 5*6 -2 =
36 +30 -2 =
66 -2=
64
36-30-2
36-32= 4
Find the length of the third side. If necessary, round to the nearest tenth.
12
13
Answer:
Submit Answer
attempt 1 out of 2
Privacy Policy Terms of Service
PLS HELP ASAP
Answers
Answer:
5
Step-by-step explanation:
Use pythagorean theorem. A^2+B^2=C^2
13 is c because it is the hypotenuse and across from the right angle
a is unknown and b is 12
A^2+12^2=13^2
A^2 +144 = 169
A^2 = 169- 144
A^2= 25
now take the sq root of both side
A = 5
Answer:
17.7
Step-by-step explanation:
6-
С
5
B
B
4-
3-
D
2-
A
А
1-
0
-7
-5
0
-6
.4
-3
-2
-1
2
3
4
5
6
-10
-2-
-3-
-4-
Which of the following sequences of transformations is used to obtain figure A'B'C'D' from ABCD?
Answers
Answer: -1
Step-by-step explanation:
Look at the patter it has
(t + 1)(t2 + 2t + 4)
find the product.
Answers
Answer:
5+5t
Step-by-step explanation:
The answer you are looking for is t^3+3t^2+6t+4.
Solution:
(t+1)(t^2+2t+4)
t^3+2t^2+4t+t^2+2t+4
t^3+3t^2+6t+4
A room is twice as long as it is broad and its height is 8 m. if the cost of painting its walls at Rs. 20 per m² is Rs 9600 , find the cost of carpeting its floor at Rs. 400 per m²
Answers
let breadth be X
length = 2x
height = 8m
rate of painting the four wall= 20/m^2
cost of painting=9600
Area of four wall= cost of painting / rate
= 9600/20
= 480m^2
again,
Area of four wall = 2 h(l+b)
or, 480=2×8(X+2x)
or, 480/16=3x
or, 30/3=X
or, X= 10m
again,
2x= 2×10m=20m
again,
Area of floor = length × breadth
= 20×10
=200m^2
again,
rate of carpeting the floor= 400/m^2
cost of carpeting the floor = rate × area
= 400× 200
= Rs. 80000
Understanding Transversals
Use the diagram to complete the statements. (please helpp)
Answers
Answer:
Step-by-step explanation:
Please answer before 2:30!!!
There are 189 apples in a basket. How many children can share them equally?
List all numbers that apply.
Answers
For the equal distribution each child can take either 1 or 3 or 7 or 9 or 21 or 27 or 63 or 189 apple.
What is equal distribution?
The distribution of a something in a way that each will get same amount.
How 189 can be divided equally?
If the distribution is equally then each child should take, either 1 or 2 or 3 an so on means same amount.
For this we will check that 189 is divisible by which numbers.
Now we can see that 189 is divisible by 1, 3, 7, 9, 21, 27, 63, 189. It is clear that each child can take either 1 or 3 or 7 or 9 or 21 or 27 or 63 or 189 apple then the distribution will be equal means every child will have same amount of apple.
Therefore, the correct answer is 1, 3, 7, 9, 21, 27, 63, 189.
Learn more: https://brainly.ph/question/4734029
#SPJ2
16. Mrs. Acosta wants to buy 2 flag pins
for each of the 168 band members for
the Fourth of July Parade. Pins cost
$0.09 each. Which is the best estimate
of the cost of the pins?
Answers
Answer: About 34 dollars
Please anyoneeeeeeee.....i am almost done just please help me
Answers
Answer:
B. XV and XY
Step-by-step explanation:
you can eliminate the top two options because those aren't rays. XV and XY are the only ones that end in X
Fifthteen of student took a math test. Eight student scored 75, five scored 82 and two scored 95. What was the average of there score
Answers
Answer:
84
Step-by-step explanation:
To find the average of the data or the mean, add 75, 82, and 95 which is 252, then 252 divided by 3 = 84. Hopefully, this helps :)
What is the midpoint of the segment shown below?
10
O A. (-1,-1)
(-11, 0)
O B. (-2, -3)
O C. (-1, -3)
- 10
10
(9,-1)
- 10
D. (-2, -1)
Answers
Answer:
(-1,-0.5)
Step-by-step explanation:
Find the solution to this problem by using the midpoint formula which is (x1+x2/2,y1+y2/2) plug in the values of y and x to get -11+9/2+0-1/2. simplify to get the solution of (-1,-0.5)
If there are:
6 red marbles
10 yellow marbles
5 green marbles
and 1 blue marble
What is the probability of picking 1 blue marble and 1 green marble?
(Once a marble is chosen it is NOT put back into the box).
(Write your answer in the form of a decimal, round to 2 places).
Answers
Answer:
0.02
Step-by-step explanation:
either picking a green then blue;
5/22 x 1/21= 5/462
or picking a blue then green;
1/22 x 5/21= 5/462
total is 10/462 which is approximately 0.02
since there was no specific order in the question i assumed you add them both.
The sporting goods store sells 6 different brands of tennis rackets and 4 different brands of tennis balls. If Amanda buys one brand of tennis racket and one brand of tennis balls, how many different combinations of brands can she buy ?
10
12
16
24
Answers
Answer:
24
Step-by-step explanation:
There are 6 different types of rackets and 4 different types of balls.
To determine the number of different combinations
6 rackets * 4 balls
24 combinations
Answer:
24
Step-by-step explanation:
What describes the correct way to convert minutes to an hour
Answers
Answer:
Yo mean correct way??
yo can divide minute by 60 to convert minute into hour
For example
To convert 10 minute into hour. then we should divide 10 by 60. 10/60
Answer:
In any conversion you have to establish ratios (or rates) for the different units being converted.
The process will be performed by a series of multiplications that will cancel out the "unwanted" units.
multiplication by one (1) does not change the value in an equation.
you have to multiply by a "series of ones" that take into account the units being converted..
for example
1 minute/60 seconds or 1 inch = 2.54 cm or 1 day = 24 hours
in your problem you have minutes... lets say you have 100 minutes
100 minutes * 1 hour minutes cancel and you have 100/60 = 1 [tex]\frac{2}{3}[/tex] hrs
60 minutes
Step-by-step explanation:
Help asap sorry for the blurry pic
Answers
Total mass = 8 kg
Mass of tool 1 = 4 kg
Mass of tool 2 = 2 kg
So,
Total mass = Mass of tool 1 + Mass of tool 2 + Mass of tool 3
=> 8 kg = 4 kg + 2 kg + Mass of tool 3
=> 8 kg = 6 kg + Mass of tool 3
=> 8 kg - 6 kg = Mass of tool 3
=> 2 kg = Mass of tool 3
A bookstore is selling books for $10 each. Which graph shows the relationship between the number of books, x, the store sold and the total amount of money, y, paid from the book sales?
Answers
Answer:
Graph B
Explanation:
Please help explanation if possible
Answers
Answer:
(x,y) —> (–1 ,1)
I hope I helped you ^_^
I need help ASAP!!! FIND THE SEGMENT Please explain how u got the answer
Answers
Answer:
x = 960
Step-by-step explanation:
Using the Altitude- on- Hypotenuse theorem
( leg of large triangle )² = ( part of hypotenuse below it) × ( whole hypotenuse), so
x² = 576 × (576 + 1024) = 576 × 1600 = 921600 ( take square root of both sides )
x = [tex]\sqrt{921600}[/tex] = 960
Ariana is a songwriter who collects royalties on her songs whenever they are played in a commercial or a movie. Ariana will earn $40 every time one of her songs is played in a commercial and she will earn $110 every time one of her songs is played in a movie. Ariana earned a total of $500 in royalties on 9 commercials and movies. Write a system of equations that could be used to determine the number of commercials and the number of movies on which Ariana's songs were played. Define the variables that you use to write the system.
Answers
c + m =9
c is variable for commercial; m is variable for movies
