Using Technology, Solve the Following Problem: the Concentration of Hexane

Multiple Choice

Using technology, solve the following problem: The concentration of hexane (a common solvent) was measured in units of micrograms per liter for a simple random sample of fourteen specimens of
Untreated ground water taken near a municipal landfill. The sample mean was 241.8 with a sample Standard deviation of 8.8. Ten specimens of treated ground water had an average hexane Concentration of 149.5 with a standard deviation of 7.4.
It is reasonable to assume that both samples come from populations that are approximately normal. Construct A 95% confidence interval for the reduction of hexane concentration after treatment.

A) (9.242, 9.960)
B) (85.407, 99.193)
C) (86.595, 98.005)
D) (9.306, 9.900)