Question

Most dermatologists recommend using sunscreens that have a sun protection factor (SPF) of at least 30. One of the authors wanted to find out whether the SPF of sunscreens used by students at her school (which is in a very sunny part of the U.S.) exceeds this value, on average.

               

1. Identify the variable of interest and whether the variable is categorical or quantitative.

a. SPF value, quantitative.

b. Students, categorical.

c. Students, quantitative.

d. Average SPF value, quantitative.

e. SPF value, categorical.

               

2. Describe the author’s parameter of interest and assign an appropriate symbol to denote it.

a. μ = mean SPF of suncreens

b. μ = number of students who use sunscreen.

c. μ = median SPF of suncreens.

               

3. Write the appropriate hypotheses using symbols.

a. H0: μ > 30 versus Ha: μ = 30.

b. H0: μ < 30 versus Ha: μ = 30.

c. H0: μ = 30 versus Ha: μ > 30.

d. H0: μ = 30 versus Ha: μ < 30.

Answer 1

TOPIC:Parameter of interest and the required null and alternative hypotheses.