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.

Find the p-value. Round to the fourth as needed.

Answer 1

Solution :

The null and alternative hypothesis is ,

H0 :   = $180,000

Ha : < $180,000

Test statistic (t) =

= ( - ) / s / n

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

Test statistic = -4.11

P(z > ) = 1 - P(z < ) =

P-value = 0.0003