when the population standard deviation is unknown the standa

when the population standard deviation is unknown, the standard error of the mean may be estimated by

s/n

sn-1

either of the above

neither of the above

QUESTION 2

For inference about means, we need to know the value of the standard deviation of the population. We estimate its value by calculating

SS/(n-1)

SS/n

either of the above

neither of the above

  

QUESTION 3

Consider the following sample of three scores: 2, 4, and 6. The best estimate of the population standard deviation is

8

2.67

4

2

QUESTION 4

For a sample of 16 cases, the best estimate of the population standard deviation is calculated to be 8.36. The best estimate of the standard error of the mean (for samples of size 16) is

.522

2.16

2.09

4.18

QUESTION 5

The t distribution is designed to correct for errors introduced when

sampling is without replacement

sampling is not random

the distribution of sample means is skewed.

the population standard deviation is estimated from the sample

QUESTION 6

In general, \"degrees of freedom\" is most clearly related to the

level of significance

value of the standard error of the mean

value of xbar

sample size

QUESTION 7

Basically, \"degrees of freedom\" refers to

freedom for n to vary

independent pieces of information

the amount of freedom xbar has to vary

alternatives we have in analyzing data

QUESTION 8

We are testing Null: = 50 against Alternative: < 50 using a sample of 7 cases. The critical value of t for = .01 is

-3.499

-3.707

-2.998

-3.143

QUESTION 9

We are testing Null: = 100 against Alternative: 100 using a sample size of 15. The critical values for t for = .10 are

1.753

1.345

1.746

1.761

  

QUESTION 10

Professor Davis reports: \"My results were not significant at the .10 level.\" From this we can infer that

p = .10

p > .10

Professor Davis used = .10 and retained NULL

Professor Davis used = .10 and rejected the NULL

	a.	s/n
	b.	sn-1
	c.	either of the above
	d.	neither of the above

Solution

when the population standard deviation is unknown, the standard error of the mean may be estimated by s/n.

For inference about means, we need to know the value of the standard deviation of the population. We estimate its value by calculating SS/(n-1)

Consider the following sample of three scores: 2, 4, and 6. The best estimate of the population standard deviation is 2.

For a sample of 16 cases, the best estimate of the population standard deviation is calculated to be 8.36. The best estimate of the standard error of the mean (for samples of size 16) is 8.36/sqrt n=8.36/4=2.09

The t distribution is designed to correct for errors introduced when the population standard deviation is estimated from the sample

In general, \"degrees of freedom\" is most clearly related to the level of significance

We are testing Null: = 50 against Alternative: < 50 using a sample of 7 cases. The critical value of t for = .01 is -3.143.

We are testing Null: = 100 against Alternative: 100 using a sample size of 15. The critical values for t for = .10 are +/- 1.761

Professor Davis reports: \"My results were not significant at the .10 level.\" From this we can infer that Professor Davis used = .10 and retained NULL