Unit 4 psych stat assignment

Directions

• In the following slide is a chart with 9 rows, each row is a practice problem

• In each problem you are given:

• an X value

• a Mean

• a Standard Deviation

• an Alpha level

• Whether it is a 1 or 2 tailed test

• (if it is one tailed you are told the direction of high/positive, or low/negative)

• For each of these problems you will practice steps 3, 4, and 5 of hypothesis testing:

• Detrmine the cutoff score

• Solve for your Z score

• Decide whether or not to reject your null hypothesis

Study Population Sample

Score Alpha Level Tails of Test

M SD X

A 100 10 80 .05 1 (low)

B 100 20 80 .01 2

C 74.3 4.8 80 .05 2

D 78 0.8 80 .01 1 (high)

E 90 4.7 80 .05 2

F 78 0.8 80 .01 2

G 76 2.3 80 .05 1 (high)

H 74 2.6 80 .01 2

I 76 2.3 80 .05 1 (low)

Answers

• A

• Step 3:

• Z cutoff = -1.64

• Step 4:

• Z = -2

• Step 5:

• Reject

Answers

• B

• Step 3:

• Z cutoff = +/-2.57

• Step 4:

• Z = -1

• Step 5:

• Fail to reject

Answers

• C

• Step 3:

• Z cutoff = +/-1.96

• Step 4:

• Z = 1.19

• Step 5:

• Fail to reject

Answers

• D

• Step 3:

• Z cutoff = 2.33

• Step 4:

• Z = 2.5

• Step 5:

• Reject

Answers

• E

• Step 3:

• Z cutoff = +/-1.96

• Step 4:

• Z = -2.13

• Step 5:

• Reject

Answers

• F

• Step 3:

• Z cutoff = +/-2.57

• Step 4:

• Z = 2.5

• Step 5:

• Fail to Reject

Answers

• G

• Step 3:

• Z cutoff = 1.64

• Step 4:

• Z = 1.74

• Step 5:

• Reject

Answers

• H

• Step 3:

• Z cutoff = +/-2.57

• Step 4:

• Z = 2.31

• Step 5:

• Fail to Reject

Answers

• I

• Step 3:

• Z cutoff = -1.64

• Step 4:

• Z = 1.74

• Step 5:

• Fail to Reject