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]

Question

Quizplus · Accepted Answer

[± ] = [49.3 ± 6.965(1.5/ 1.732)] = [49.3 ± 6.03] = [43.27, 55.33]

An Experiment Was Conducted to Determine the Effectiveness of a Method