Question

An article in Environment International (Vol. 18, No. 4, 1992) described an experiment in which the amount of radon released in showers was investigated. Radon-enriched water was used in the experiment, and six different orifice diameters were tested in shower heads. The data from the experiment are shown in the following table

Orifice Diameter	Radon Released (%)
0.37	80	83	83	85
0.51	75	75	79	79
0.71	76	76	83	77
1.02	67	72	84	74
1.4	62	65	88	85
1.99	60	61	64	66

a. Does the size of the orifice affect the mean percentage of radon released? What conclusions would you draw? Use a=0.05

b. Find the P-value for the F-statistic in part (a)

c. Find a 95% confidence interval on the mean percent of radon released when the orifice diameter is 1.40.

Answer 1

Solution :

Given that