Preliminary Data Analyses Indicate That You Can Reasonably Use Nonpooled

question 51

Essay

Preliminary data analyses indicate that you can reasonably use nonpooled t-procedures on the given data. Apply anonpooled t-test to perform the required hypothesis test, using either the critical-value approach or the P-value approachas indicated.
-A paint manufacturer wishes to compare the drying times of two different types of paint. Independent random samples of 11 cans of type A and 9 cans of type B were selected and applied to similar surfaces. The drying times (in minutes)were recorded. The summary statistics are as follows. $\begin{array} { r | r } \text { Type A } & \text { Type B } \\ \hline \bar { x } _ { 1 } = 75.4 & \bar { x } _ { 2 } = 64.7 \\ \mathrm {~s} _ { 1 } = 4.5 & \mathrm {~s} _ { 2 } = 5.1 \\ \mathrm { n } _ { 1 } = 11 & \mathrm { n } _ { 2 } = 9 \end{array}$
Do the data provide sufficient evidence to conclude that the mean drying time for type A differs from the mean drying time for type B? Perform a t-test at the 1% significance level. Use the P-value approach.