Practice Test 2 Answers STA 2023

1) a) descriptive b) inferential

2) a) double-blind b) pairing

3)

4) s = .03

5) 3752

6)

7)

8)

9)

10)

11) a) .52 b) 7.08 m 8.12

12) a) 6.7 b) 97.3 m 110.7

13) a) ZInterval b) $41768 m $45640

14) a) 1-PropZInt b)

15) a) TInterval b) 72.2 m 79.8

16) systematic

17) cluster

18) random

19) 174

20) H_o: p = .058

H_a: p < .058 (claim)

One-tail

Reject H_o

The data supports the claim that the failure rate is now lower.

21) H_o: p = .09 (claim)

H_a: p .09

Two-tail

Fail to reject H_o

The data supports the claim that 9% of college students carry such weapons.

22) H_o: p = .2

H_a: p > .2 (claim)

One-tail

z = 1.645

z = 1.73

Reject H_o

The data supports the claim that more than 20% watch “60 Minutes”.