A Random Sample of 5726 Telephone Numbers from a Certain $p _ { 1 } = .20 \text { and } p _ { 2 } = .18$

question 13

Essay

A random sample of 5726 telephone numbers from a certain region taken in March 2002 yielded 1105 that were unlisted, and 1 year later a sample of 5384 yielded 980 unlisted numbers.
a. Test at level .10 to see whether there is a difference in true proportions of unlisted numbers between the two years.
b. If $p _ { 1 } = .20 \text { and } p _ { 2 } = .18$
what sample sizes (m = n) would be necessary to detect such a difference with probability .90?

Interpret and validate regression assumptions using graphical methods (scatter plots, residual plots, normal probability plots).

Understand the concepts of ANOVA designs and their applications.

Identify the appropriate ANOVA design based on experimental conditions.

Comprehend the hypothesis testing framework in the context of ANOVA.