Question

A public health agency took a poll to determine how many people were regularly going to the dentist. the public health department manager recalls from her statistics class in college that the poisson distribution might describe such events. A randon sample of 150 citizens is taken. the numberof dental visits per year reported in the sample as well as the observed frequencies are shown below.

Annual Dentist Visits

0,1,2,3,4

Observed Frequency

21,37,44,30,14

more then 4 4

The manager tests the hypothesis that annual dental visits are Poisson distributed with a population mean equal to 190. Hersignificance level is 0.05.

a. state the null and alternative hypotheses.

b. what are the appropriate degrees of freedom?

c. identify the critical value.

d. Calculate the expected frequencies.

Answer 1