An Experiment Was Conducted to Determine the Effectiveness of a Method

question 118

Multiple Choice

An experiment was conducted to determine the effectiveness of a method designed to remove oil wastes found in soil. Three contaminated soil samples were treated. After 95 days, the percentage of contamination removed from each soil sample was measured, with a mean of 49.3 percent and a standard deviation of 1.5 percent. Estimate the mean percentage of contamination removed at a 98 percent confidence level.

• A) [48.36, 50.24]
• B) [43.27, 55.33]
• C) [47.29, 51.31]
• D) [47.88, 50.72]
• E) [46.47, 52.13]

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Definitions:

Confidence Coefficient

The probability level associated with a confidence interval, indicating the degree of certainty that the parameter lies within the interval.

Population Distribution

The spread of characteristics or variables across all members of a defined group or population.

Confidence Interval

A range of values, derived from sample statistics, that is believed, with a certain level of confidence, to contain the population parameter of interest.

Credit Sales

Sales made by a business for which payment will be made at a later date, as opposed to immediate cash sales.