Children with Down Syndrome generally show a pattern of ret

. Children with Down Syndrome generally show a pattern of retarded mental development, although some achieve higher intellectual levels than others. The intellectual achievements of Down Syndrome children have been studied by numerous investigations, and several different types of chromosomal abnormalities associated with the syndrome have been identified. Two such abnormalities are called trisomy 21 and mosaicism. The levels of intellectual functioning of trisomy 21 and Mosaic Down Syndrome were compared in the paper

Solution

Set null and alternate as

H0: Means are the same (mu1=mu2)

Ha: after treatment mean > before treatment

mu1<mu2

Left tailed test

Means and std dev are given below for the two groups

Group I Group II

t statistic = 3.547

p value = 0.00039

As p < 0.05 reject null hypothesis.

There is difference after the treatment.