Question
Population Mean (MULTIPLE CHOICE)
10. 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 were recorded. The following 98% confidence interval was obtained for ui uz, the difference between the mean drying time for paint cans of type A and the mean drying time for paint cans of type B: 4.90 hrs H1 H2 17.50 hrs. What does the confidence interval suggest about the population means? Question 10 options: The confidence interval includes only positive values which suggests that A) 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. The confidence interval includes 0 which suggests that the two population B) 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. 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 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
Explanation / Answer
The correct answer is : - (B )
The confidence interval includes 0 (zero) which suggest that the two population means might be equal. There doesn't appear a significant difference between the mean drying for the paint type A and the mean drying for the paint type B. The modification does not seem to be effective in reducing drying times.