What does the confidence interval suggest about the population​ means?

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A paint manufacturer made a modification to a paint to speed up its drying time. Independent simple random samples of 11 cans of type A​ (the original​ paint) and 9 cans of type B​ (the modified​ paint) were selected and applied to similar surfaces. The drying​ times, in​ hours, were recorded. The summary statistics are as follows.

What does the confidence interval suggest about the population​ means?
 
A paint manufacturer made a modification to a paint to speed up its drying time. Independent simple random samples of 11 cans of type A (the original paint) and 9 cans of type B (the modified paint) were selected and applied to
similar surfaces. The drying times, in hours, were recorded. The summary statistics are as follows.
Туре А
X, = 76.3 hr
S1 =4.5 hr
n, = 11
Туре В
X2 = 65.1 hr
$2 =5.1 hr
n2 = 9
The following 98% confidence interval was obtained for p, - P, the difference between the mean drying time for paint cans of type A and the mean drying time for paint cans of type B. What does the confidence interval suggest
about the population means?
4.90 hr <p, - p, < 17.50 hr
O A. The confidence interval includes only positive values which suggests that the mean drying time for paint type A is greater than the mean drying time for paint type B. The modification seems to be effective in reducing
drying times.
O B. The confidence interval includes only positive values which suggests that the mean drying time for paint type A is smaller than the mean drying time for paint type B. The modification does not seem to be effective in
reducing drying times.
OC. The confidence interval includes 0 which suggests that the two population means might be equal. There doesn't appear to be a significant difference between the mean drying time for paint type A and the mean drying
time for paint type B. The modification does not seem to be effective in reducing drying times.
O D. The confidence interval includes only positive values which suggests that the two population means might be equal. There doesn't appear to be a significant difference between the mean drying time for paint type A and
the mean drvina time for paint tvpe B. The modification does not seem to be effective in reducina drvina times.
Transcribed Image Text:A paint manufacturer made a modification to a paint to speed up its drying time. Independent simple random samples of 11 cans of type A (the original paint) and 9 cans of type B (the modified paint) were selected and applied to similar surfaces. The drying times, in hours, were recorded. The summary statistics are as follows. Туре А X, = 76.3 hr S1 =4.5 hr n, = 11 Туре В X2 = 65.1 hr $2 =5.1 hr n2 = 9 The following 98% confidence interval was obtained for p, - P, the difference between the mean drying time for paint cans of type A and the mean drying time for paint cans of type B. What does the confidence interval suggest about the population means? 4.90 hr <p, - p, < 17.50 hr O A. The confidence interval includes only positive values which suggests that the mean drying time for paint type A is greater than the mean drying time for paint type B. The modification seems to be effective in reducing drying times. O B. The confidence interval includes only positive values which suggests that the mean drying time for paint type A is smaller than the mean drying time for paint type B. The modification does not seem to be effective in reducing drying times. OC. The confidence interval includes 0 which suggests that the two population means might be equal. There doesn't appear to be a significant difference between the mean drying time for paint type A and the mean drying time for paint type B. The modification does not seem to be effective in reducing drying times. O D. The confidence interval includes only positive values which suggests that the two population means might be equal. There doesn't appear to be a significant difference between the mean drying time for paint type A and the mean drvina time for paint tvpe B. The modification does not seem to be effective in reducina drvina times.
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