The Concentration of Hexane (A Common Solvent) Was Measured in Units

question 22

Multiple Choice

The concentration of hexane (a common solvent) was measured in units of micrograms per liter for a simple random sample of twelve specimens of untreated ground water taken near a municipal Landfill. The sample mean was 720.2 with a sample standard deviation of 8.8. Eleven specimens of Treated ground water had an average hexane concentration of 695.1 with a standard deviation of 9.1.
It is reasonable to assume that both samples come from populations that are approximately normal. Construct A 90% confidence interval for the reduction of hexane concentration after treatment.

• A) (23.6, 26.6)
• B) (18.3, 31.9)
• C) (21.8, 28.4)
• D) (22.2, 28.0)

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Definitions:

Positive Externalities

Benefits that are enjoyed by a third-party or society as a whole as a result of an economic transaction or activity, without them directly paying for it.

Utility Function

A mathematical representation that describes how consumers rank preferences among different commodity bundles.

Campers' Utility

A hypothetical measure of the satisfaction or happiness that campers gain from participating in camping activities or utilizing camping facilities.

Externalities

Economic side effects or consequences that affect uninvolved third parties; can be either positive or negative.