Question

Question 1

The main reason a research uses a t-test instead of a z-test is when little is known about population (mean and standard deviation).

1) True

2) False

Question 2

Values in the t‐table are not actually listed by sample size but by degrees of freedom (df).

1) True

2) False

Question 3

A 90 percent confidence level is equivalent to an alpha level of 0.10

1) True

2) False

Question 4

A professor wants to know if her introductory statistics class has a good grasp of basic math at the start of the semester. Six students are chosen at random from the class and given a math proficiency test. The professor wants the class as a whole to be able to score above 70 on the test. The six students get scores of 62, 92, 75, 68, 83, and 95. The professor has 90 percent confidence that the mean score for the class on the test would be above 70?

1) True

2) False

Question 5

The critical value of t‐table for a study with 6 participants with alpha set @ .1 one tail is 1.711

1) True

2) False

Question 6

What is the critical value of t for a one tailed test for a sample of 10 participants if the alpha is set at .05

1) 2.145

2) 1.711

3) 2.021

4) 1.8333

Question 7

What is the critical value of t for a one tailed test for a sample of 25 participants if the alpha is set at .05

1) 2.145

2) 1.711

3) 2.357

4) .677

Question 8

What is the critical value of t for a two tailed test for a sample of 43 participants if the alpha is set at .05

1) 2.021

2) 2.145

3) 1.711

4) 2.247

Answer 1

Ans 1 ) it is false because when population standard deviation is known we will use z test not t test.

Ans 2) it is true.

Values in the t‐table are not actually listed by sample size but by degrees of freedom (df).

Ans 3 ) yes it is true that of significance level is 0.90 then alpha =1-0.90=0.10

Ans 4 ) using minitab >stat>basic stat>one sample t

The 90 %confidence interval is (68.34,90)

Since the confidence interval contail value less than 70

So the given statement is false.

Ans 5 ) false because from t table, the t value is 1.476

Ans 6) option 4 is correct

From t table the t value for one tailed is 1.833.

Ans 7) option 2 is correct

From t table the t value for one tailed is 1.711

Ans 8) option 1 is correct

Tye t value is 2.021