Question

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

a 2.021

b 2.247

c 1.711

d 2.145

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?

T or F

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

a 1.8333

b 2.021

c 1.711

d 2.145

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

a .677

b 1.711

c 2.357

d  2.145

Answer 1

Solution :

Given that,

sample size = n = 43

Degrees of freedom = df = n - 1 = 43 - 1 = 42

= 0.05

/ 2 = 0.05 / 2 = 0.025

t _/2,df = t_0.025,42 = 2.021

Critical value = 2.021

T

sample size = n = 10

Degrees of freedom = df = n - 1 = 10 - 1 = 9

= 0.05

t _,df = t_0.05,9 = 1.8333

Critical value = 1.8333

sample size = n = 25

Degrees of freedom = df = n - 1 = 25 - 1 = 24

= 0.05

t _,df = t_0.05,24 = 1.711

Critical value = 1.711