The drying time, in minutes, of two different brands of latex paint were recorded. In a...

The drying time, in minutes, of two different brands of latex paint were recorded. In a random sample of 6 units of brand 1, the mean average drying time is found to be 70.83 minutes with standard deviation of 15.09. However, for a random sample of 9 units of brand 2, the mean average drying time is found to be 79.33 minutes with standard deviation of 8.08. Assume normal populations. Note: Round all the final numbers to 2 decimal places.

a) (3 points) Create and interpret a 95% confidence interval for the average drying time for brand 1. Note: Do the calculations one time by hand and the other time by R and show your code/output.

b) (3 points) Create and interpret a 95% confidence interval for the average drying time for brand 2. Note: Do the calculations one time by hand and the other time by R and show your code/output.

c) (2 points) In comparing the confidence intervals created in (a) and (b) does there appear to be a difference in the average drying time between brand 1 and brand 2? Explain.

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c) Since there is a significant difference in lower bound of the two confidence intervals, so there seems to appear to be a significant difference in the average drying time between brand 1 and brand 2.

orchestra answered 1 year ago

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