# t-test

In this exercise, assume that a simple random sample has been selected from a normally distributed population. Find the null and alternative hypotheses, test statistic, P-value (or range of P-values), critical value(s), and state the final conclusion.

Claim: The mean life span of desktop PCs is less than 7 years.

Sample data: n = 21, = 6.8 years, s = 2.4 years. The significance level is α = 0.05.

https://brainmass.com/statistics/students-t-test/perform-left-tailed-t-test-207933

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Finding Test Components

In this exercise, assume that a simple random sample has been selected from a normally distributed population. Find the null and alternative hypotheses, test statistic, P-value (or range of P-values), critical value(s), and state the final conclusion.

Claim: The mean life span of desktop PCs is less than 7 years.

Sample data: n = 21, x-bar = 6.8 years, s = 2.4 years. The significance level is α = 0.05.

Solution:

This is an example of a small sample hypothesis test for a population mean The significance level is ...

#### Solution Summary

This solution shows all calculations with explanations for a one-tailed t-test.