A paint manufacturer wished to compare the drying times of two different types of paint. independent simple 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 hours, were recorded. the summary statistics are as follows. determine a 98% confidence interval for the difference, between the mean drying time for type a and the mean drying time for type

b. 4.25 to 15.35 hours 4.48 to 15.12 hours 4.18 to 15.42 hours 4.32 to 15.28 hours