STA 2023 Worksheet #12 Answers

1) H_o: m = 75 claim

H_a: m 75

Two-tail

Crit. z = 1.96

Calc. z = 2

Reject H_o

Data does not support claim that the mean is 75.

2) H_o: m = 2.25

H_a: m > 2.25 claim

One-tail

Crit. z = 2.05

Calc. z = 1.53

Fail to reject H_o

Data does not support claim that mean GPA is greater than 2.25

3) H_o: m = 75 claim

H_a: m 75

Two-tail

Crit t = 2.093

Calc. t = .596

Fail to reject H_o

Data supports claim that mean is 75.

4) H_o: m = 2.55

H_a: m < 2.55 claim

One-tail

Crit. t = - 1.714

Calc. t = - 2.449

Reject H_o

Data supports the claim that mean GPA is less than 2.55.

5) H_o: m = 600 claim

H_a: m 600

Two-tail

Crit. z = 2.575

Calc. z = - 2.108

Fail to reject H_o

Data supports claim that mean is 600.

6) H_o: m = 1000

H_a: m < 1000 claim

One-tail

Crit. t = - 2.132

Calc. t = - 1.827

Fail to reject H_o

Data does not support claim that mean is less than $1000.

7) H_o: m = 92.64 claim

H_a: m 92.64

Two-tail

Crit. z = 1.96

Calc. z = - 0.72

Fail to reject H_o

Data supports claim that mean is 92.64.

8) H_o: m = 3.35

H_a: m > 3.35 claim

One-tail

Crit. t = 1.753

Calc. t = 1.978

Reject H_o

Data supports claim that mean is greater than 3.35.