Question

A random sample of 20 family practitioners in a city had an average salary of $150,250 with a standard deviation of $32,400. Can you conclude that the true average family practitioner salary in this city is less than $180,000? It has been confirmed that the these salaries come from a normal distribution.

What is the test statistic? Round to the fourth as needed.

Answer 1

Solution:

The null and alternative hypothesis is ,

H0 :  $\mu$ = $180,000

Ha : $\mu$ < $180,000

Test statistic (t) =

= ($\bar x$ - $\mu$ ) / s / $\sqrt$ n

= (150,250 - 180,000) / 32,400 / $\sqrt$ 20

Test statistic = -4.11