1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Thepotemich [5.8K]
3 years ago
14

The test scores of a geometry class are given below. 90, 75, 72, 88, 85 The teacher wants to find the variance for the class pop

ulation. What is the value of the numerator of the calculation of the variance?
Mathematics
2 answers:
Oliga [24]3 years ago
7 0
Variance is given by s^2 = [summation (x - mean)^2] / n.
mean = (90 + 75 + 72 + 88 + 85) / 5 = 82
Variance = [(90 - 82)^2 + (75 - 82)^2 + (72 - 82)^2 + (88 - 82)^2 + (85 - 82)] / 5
= [8^2 + (-7)^2 + (-10)^2 + 6^2 + 3^2] / 5
= (64 + 49 + 100 + 36 + 9] / 5
= 258 / 5
=258.


Kazeer [188]3 years ago
5 0
<h2>Answer:</h2>

The value of the  numerator of the calculation of the variance= 258

and Variance= 51.6

<h2>Step-by-step explanation:</h2>

We know that in order to calculate the variance we need to follow following steps:

  •   First calculate mean.
  • Then subtract each of the data points from means and square the difference quantity.
  • Lastly calculate the mean of these squared quantity.

The data points are:

   90, 75, 72, 88, 85

The mean of these data points are:

Mean=\dfrac{90+75+72+88+85}{5}\\\\\\Mean=\dfrac{410}{5}\\\\\\Mean=82

Now on finding the difference terms i.e.

90-82=8

75-82= -7

72-82= -10

88-82=6

and  85-82=3

The square of these difference term is:

8²=64

(-7)²=49

(-10)²=100

6²=36

and  3²=9

Hence, the mean of these squared quantity i.e. Variance is:

Variance=\dfrac{64+49+100+36+9}{5}\\\\\\Variance=\dfrac{258}{5}\\\\\\Variance=51.6

You might be interested in
Please help! What’s the greatest common factor?? (#10)
pshichka [43]
(x-1) (x + 2) • 3

factor the polynomial...

Polynomial - an algebraic expression consisting of one or more some terms each term consider consisting of a constant multiple and one or more variables raised to integral powers
3 0
3 years ago
A country's population in 1993 was 116 million.
labwork [276]

Answer:

124 million in 2007

Step-by-step explanation:

This is a proportion match question, we consider 121-116 to represent a 9 year change = 5 rate of change per 9 years. We need to find one year so we divide 5/9=0.55 per year growth. =2002- 2007= 0.55 million x 5 = 2.8million growth add 121 million = 121 =123.8 in 2007 = 124 million to nearest m.

7 0
3 years ago
The zoo is creating a new tank for some of its fish. The zoo wants the tank to be a cube and be able to hold 3,375 cubic feet of
Verizon [17]

Answer:

³√3375

Step-by-step explanation:

Hope this will help guys

3 0
2 years ago
tom took a trip of 1,020 miles. he traveled by train at 55 miles an hour and the same number of hours by plane at 285mph how man
Kamila [148]
D = vt

Distance traveled by train
d = 55t
Distance traveled by plane
d = 285t
Total distance
d = 1020

So, you do:
distance traveled by plane + distance traveled by train =  total distance
(55t) + (285t) = 1020

Solve for t
t = 3 hours

t is the time traveled by each so 3 hrs traveled by train and 3 hrs traveled by plane

Total time  = 3 + 3 = 6 hours







8 0
3 years ago
Complete each statement in the steps to solve x2 – 6x – 7 = 0 using the process of completing the square. Isolate the constant b
Tomtit [17]
"Isolate the constant by adding 7 to both sides of the equation."
This step separates the non-squareable 7 and the squareable x^2 - 6x .

"Add 9 to both sides of x^2 - 6x = 7 to form a perfect square trinomial while keeping the equation balanced."
After separating the non-squareable, add the number which makes the first or left side a perfect square trinomial. The formula to find the number is: c =  {\frac{b}{2}  }^{2} .
When we plug the values: c =  { \frac{ - 6}{2} }^{2}
Simplify: c =  {( - 3)}^{2}  = 9

"Write the trinomial x^2 - 6x + 9 as (x - 3) squared."
When you factor x^2 - 6x + 9 , you will get (x - 3) \times (x - 3) .

"Use the square root property of equality to get x - 3 = ±  \sqrt{16} ."
The 16 is coming from the part when we add 9. We needed 9 on the left side for a perfect square, but to protect the balance of the equality, we need to add 9 to the right side too. When we add 7 and 9, we got 16, and that is where it came from.

"Isolate the variable x to get solutions of -1 and 7."
To isolate x we branched the plus-minus sign:
x - 3 = 4 \: \:  \:  x = 4 + 3 = 7 \\  \\ x - 3 =  - 4 \:  \:  \: x =  - 4 + 3 =  - 1
8 0
3 years ago
Read 2 more answers
Other questions:
  • Factor-20x2 + 13x + 21.<br> How do you solve this
    5·1 answer
  • Xander goes to the movies with his soccer team. Each team member buys a ticket and two
    13·1 answer
  • What is the value of x
    7·2 answers
  • Termeni unei adunari sunt 382 145 si 286 care este suma lor
    12·1 answer
  • A smoothie shop has 40 stores and 55% of the stores are in california the rest of the stores are in nevada.how many are in nevad
    13·1 answer
  • Angie and Kelly are playing a card game. Angie has 37 points. She has 5 points less than Kelly. How many points does Kelly have?
    9·2 answers
  • What is the percentage of 690 out of 800
    8·2 answers
  • I think of a number, then divide by 8, then
    10·2 answers
  • Let me know if you know the answer to this thank you​
    10·1 answer
  • El precio de un auto era de &amp;725000. Me han rebajado un 15% por pagarlo al contado. ¿Cuánto debemos abonar con la rebaja?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!