# Hypothesis Test

For the attached spreadsheet assume equal variances for the two populations.

A) Test the null hypothesis that the average length of service for males is the same as for females.

B) Test the null hypothesis that the average length of service for individuals without prior call center experience is the same as those with experience.

C) Test the null hypothesis that the average length of service for individuals with a college degree is the same as for individuals without a college degree.

D) Now conduct tests of hypothesis for equality of variances. Were your assumptions of equal variances valid? If not, repeat the test(s) for means using the unequal variance test.

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#### Solution Preview

Problem:

For the attached spreadsheet assume equal variances for the two populations.

A) Test the null hypothesis that the average length of service for males is the same as for females.

B) Test the null hypothesis that the average length of service for individuals without prior call centre experience is the same as those with experience.

C) Test the null hypothesis that the average length of service for individuals with a college degree is the same as for individuals without a college degree.

D) Now conduct tests of hypothesis for equality of variances. Were your assumptions of equal variances valid? If not, repeat the test(s) for means using the unequal variance test.

Solution-A:

Step-1: Null and Alternate Hypothesis:

Null Hypothesis: The average length of service for males is the same as that for females.

:

Alternate Hypothesis: The average length of service for males is not the same as that for females.

:

Step-2: Analysis Plan:

We shall use t-test assuming equal variances to test the given hypothesis.

We shall use significance level, α=0.05.

Step-3: Critical Value and Decision Rule:

Since the alternative hypothesis is the given test is a two-tailed t-test.

Degree of freedom,

From the t-distribution table, the critical value of the test statistic for a two-tailed test at and is given as

Decision Rule:

Reject if

Step-4: Test Statistic:

t-Test: Two-Sample Assuming Equal Variances

Male Female

Mean 1.76081 2.01318

Variance 0.73519 1.62713

Observations 33 37

Pooled Variance 1.20739

Hypothesized Mean Difference 0

df 68

t ...

#### Solution Summary

This solution is comprised of detailed explanation and step-by-step calculation of the given problems. Calculations have been shown both in text and EXCEL for better understanding. The solution provides students with a clear perspective of the underlying concepts.