Question

1. here are several parts to this question so make sure you are answering each part. A researcher collects the following sample of scores: 3, 5, 6, and 10. What is the mean?

QUESTION 5

1. What is value for Σ(X – M)?

QUESTION 6

1. What is the Sum of Squares?  

QUESTION 7

1. What are the degrees of freedom?

QUESTION 8

1. What is the variance? Round to three decimal places.

QUESTION 9

1. What is the standard deviation? Round to three decimal places.

A sample of n = 10 scores has a M = 7 and s = 2. Two points is added to every score. Now, what is the standard deviation?

A sample of n = 10 scores has a M = 7 and s = 2. Every score is multiplied by 8. Now, what is the mean?

A sample of n = 10 scores has a M = 7 and s = 2. Every score is multiplied by 8. Now, what is the standard deviation?

A population of scores has a standard deviation of 12. What is the variance?

A population of scores has a variance of 81. What is the standard deviation?

Answer 1

The sample data is

The sample mean is given by

Q5)

Q6)

Q7)

Number of degrees of freedom is

Q8) The Variance of the sample is given by

Q9) The standard deviation is the positive square root of the variance

So standard deviation is

Q10) By changing the origin the standard deviation doesn't change. So by adding any constant to every score the standard deviation doesn't change

hence standard deviation is 2

Q11) If each score is multiplied by 8, The mean is also multiplied by 8

So new mean is

Q12) If each score is multiplied by 8, The standard deviation is multiplied by

So, new standard deviation is

Q13) As Variance is square of standard deviation so

Variance is

q14) Since standard deviation is positive square root of variance

hence standard deviation is