Question

1. Beginning readers are assigned at random to be taught reading by two different methods. After a year, all the children are given the same test of reading achievement. The results for the two samples are tabled below (higher numbers indicate better performance).
   1. Estimate the magnitude of the effect of Method. State your result in English.
   2. Get the 95% confidence interval to estimate the mean difference between the 2 methods and state your outcome in English.
   3. Based on your confidence interval, can you say whether there is a significant difference between the methods? What is your rationale?

	Method A	Method B
Mean =	68	75
Standard Deviation =	9.0	10.0
n =	25	30

Answer 1

Here we have two methods so we used a here independent two-sample t-test

using Two-sample t-test:

Hypothesis:

.Null hypothesis: H0:

Alternative hypothesis: H1:

Test statistic:

t = 2.7039
  df = 53
the standard error of difference = 2.589

The two-tailed P value equals 0.0092

a) Here 0.0092<0.05 so we reject H0 so it is a statistical significant difference in method A and Method B
b) 95% confidence interval of this difference: From -12.19 to -1.81

The mean of Group One minus Group Two equals -7.00

c) There is a statistical difference between method A And method B