The Quality Control Manager of a Tire Company Wishes to Estimate

Multiple Choice

The quality control manager of a tire company wishes to estimate the tensile strength of a standard size of rubber used to make a class of radial tires.A random sample of 61 pieces of rubber from different production batches is subjected to a stress test.The test measures the force (in pounds) needed to break the rubber.According to the sample results,the average pressure is 238.4 pounds with a population standard deviation of 35 pounds.Determine the 98 percent confidence interval.

A) $\left[ \begin{array} { l l } 227.96 & 248.82\end{array} \right]$
B) $[ 236.64 \quad 240.16 ]$
C) $\left[ \begin{array} { l l } 233.63 & 243.17\end{array} \right]$
D) $\left[ \begin{array} { l l } 229.21 & 247.59\end{array} \right]$