Question

4) In order to test the difference in populations means, samples were collected for two independent populations where the variances are assumed equal and the population normally distributed. The following data resulted. Find the value of the pooled variance ad 99% CI. Population 1 Population 2 - 107 x 112 s 14 n 25 - 28

this is not a true or false

Answer 1

Given:

Pooled variance can be computed using the formula:

$s_{p}^{2}=rac{(n_{1}-1)s_{1}^{2}+(n_{2}-1)s_{2}^{2}}{n_{1}+n_{2}-2}$

Substituting the values,

= 245.235

Hence, pooled variance = 245.235

The 99% CI for difference in means can be computed using the formula:

Substituting the values,

Where t_0.05,51 can be obtained using the excel function:

We get t = 2.676

Hence,

=

= ( -6.53,16.53)

Hence, the 99% CI is given by ( -6.53,16.53)