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3 years ago

What is the standard deviation

Mathematics

1 answer:

pshichka [43]3 years ago

7 0

Answer:

The Standard Deviation is a measure of how spread out numbers are.

Its symbol is σ (the greek letter sigma)

The formula is easy: it is the square root of the Variance. So now you ask, "What is the Variance?"

Variance

The Variance is defined as:

The average of the squared differences from the Mean.

To calculate the variance follow these steps:

Work out the Mean (the simple average of the numbers)

Then for each number: subtract the Mean and square the result (the squared difference).

Then work out the average of those squared differences. (Why Square?)

Step-by-step explanation:

You might be interested in

One cell phone plan charges $20 per month plus $0.15 per minute used. A second cell phone plan charges $35 per month plus $0.10

erica [24]

Answer:

300 minutes

Step-by-step explanation:

Let

x----> the numbers of minutes used

y ---> the cost per month

we know that

First cell phone plan

y=0.15x+20 ---> equation A

Second cell phone plan

y=0.10x+35 ---> equation B

equate the equation A and equation B

0.15x+20=0.10x+35

Solve for x

0.15x-0.10x=35-20

0.05x=15

x=15/0.05

x= 300 minutes

Find the cost y

y=0.15(300)+20 =$65

That means

For x=300 minutes

The cost for both calling plans is y=$65

6 0

3 years ago

An author argued that more basketball players have birthdates in the months immediately following July 31, because that was the

Lady_Fox [76]

Answer:

There is sufficient evidence to warrant rejection of the claim that professional basketball players are born in different months with the same frequency.

Step-by-step explanation:

In this case we need to test whether there is sufficient evidence to warrant rejection of the claim that professional basketball players are born in different months with the same frequency.

A Chi-square test for goodness of fit will be used in this case.

The hypothesis can be defined as:

H₀: The observed frequencies are same as the expected frequencies.

Hₐ: The observed frequencies are not same as the expected frequencies.

The test statistic is given as follows:

$\chi^{2}=\sum{\frac{(O-E)^{2}}{E}}$

The values are computed in the table.

The test statistic value is $\chi^{2}=128.12$ .

The degrees of freedom of the test is:

n - 1 = 12 - 1 = 11

Compute the p-value of the test as follows:

p-value < 0.00001

*Use a Chi-square table.

p-value < 0.00001 < α = 0.05.

So, the null hypothesis will be rejected at any significance level.

Thus, there is sufficient evidence to warrant rejection of the claim that professional basketball players are born in different months with the same frequency.

6 0

3 years ago

What are the missing numbers in the data set? Assume the numbers are in order

prohojiy [21]

Answer:

This answer is 42

Step-by-step explanation:

42 - 24 = 18

6 0

2 years ago

I need it urgent now

Ray Of Light [21]

So the answer for number 3 is p because p is the only one right on top of 4

But I dont know the answer for number 4 but I think its 2 I might be way off but its my guess.

Hope number 3 helps

6 0

2 years ago

Which linear equations does the graph show the solution to? Select all that apply. y = 2x + 13 y = –x – 2 y = 3x – 5 y = negativ

salantis [7]

Answer:

y = 2x + 13

y = –x – 2

Step-by-step explanation:

The options are:

y = 2x + 13

y = -x - 2

y = 3x - 5

y= -(1/2)x + 6

y = -2x - 2

The graph is shown in the figure attached. There, point (-5, 3) is shown. Replacing it into the equations we get:

y = 2(-5) + 13 = 3 (so, it is a solution)

y = -(-5) - 2 = 3 (so, it is a solution)

y = 3(-5) - 5 = -20 ≠ 3 (so, it isn't a solution)

y= -(1/2)(-5) + 6 = 8.5 ≠ 3 (so, it isn't a solution)

y = -2(-5) - 2 = 8 ≠ 3 (so, it isn't a solution)

6 0

3 years ago

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