An Experiment Was Conducted to Determine the Effectiveness of a Method

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) $\left[ \begin{array} { l l } 48.36 & 50.24\end{array} \right]$
B) $[ 43.27 \quad 55.33 ]$
C) $\left[ \begin{array} { l l } 47.29 & 51.31\end{array} \right]$
D) $[ 47.88$$\quad$$\quad$$50.72 ]$
E) $[ 46.47 \quad 52.13 ]$