Z = (mean1 - mean2)/standard error (SE) of difference between means
SEdiff = √(SEmean1^2 + SEmean2^2)
SEm = SD/√n
If only one SD is provided, you can use just that to determine SEdiff.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score. However, you are lacking the n values for your samples.
Based on the information given for each of the following studies, decide whether to reject the null hypothesis.For each, give (a) the Z-score cutoff (or cutoffs) on the comparison distribution at which the null hypothesis should be rejected(b) the Z score on the comparison distribution for the sample score, and (c) your conclusion. Assume that all populations are normally distributed Population
Study ì ó Sample Score p Tails of Test
A
100.0
10.0
80
.05
1 (low predicted)
B
100.0
20.0
80
.01
2
C
74.3
11.8
80
.01
2
D
16.9
1.2
80
.05
1 (low predicted)
E
88.1
12.7
80
.05 2
1 answer