Question

Flu cases this past flu season in the LRSD (n=500) were 15 per week. For the entire state, the weekly average was 16 and the standard deviation was 15.1. Are the kids in Little Rock as sick as the kids throughout the state? Test the hypothesis of no difference, and use an alpha of .05.

How would I answer this using the five step model for hypothesis testing? How do I know what which sampling distribution to use?

Answer 1

Answer)

As the population standard deviation is known here

We can use standard normal z table to conduct the test

Null hypothesis Ho : u = 16

Alternate hypothesis Ha : u not equal to 16

Test statistics z = (sample mean - claimed mean)/(s.d/√n)

Z = (15-16)/(15.1/√500) = -1.48

From z table, P(z<-1.48) = 0.0694

As the test is two tailed

P-value = 2*0.0694 = 0.1388

As the obtained p-value is greater than given significance 0.05

We fail to reject the null hypothesis Ho

So, we do not have enough evidence to conclude that difference exist