Answer:
Answers are I two options
Explanation:
THe question is about the confidence interval of difference of two groups
From the given data we find that mean difference =-25.82
Sample size of group I = 41 and group 2 =36
Hence for difference of means degree of freedom = 41+36-2=75
Since df >30, z critical 99% i.e. 2.58 can be used
Std error for difference =2.280
Hence for 99% confidence interval
margin of error = ±2.58(2.28)
=±5.91
Confidence interval lower bound =-25.82-5.91 =-31.73
Upper bound = -25.82+5.91 =-19.91
From the given five values we find that
24.12 and 26.71 lie within this interval