Question

One researcher claims the national average time spent on social media is 4 hours per week. A random sample of 404 individuals showed a sample of 4.2 hours per week. If national standard deviation is known to be 1.8, test if the true national average is greater than the researcher’s claim when α=.05.

Answer 1

n = 404

The test hypothesis is

This is a one-sided test because the alternative hypothesis is formulated to detect the difference from the hypothesized mean on the upper side
Now, the value of test static can be found out by following formula:

For . Since , we reject the null hypothesis in favor of the alternative hypothesis .
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