Construct the Indicated Confidence Interval for the Difference Between the Two

question 4

Multiple Choice

Construct the indicated confidence interval for the difference between the two population means. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. 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.

Construct a 99 % confidence interval for $\mu _ { 1 } - \mu _ { 2 }$ the difference between the mean drying time for paint type A and the mean drying time for paint type B.

• A) \(5.85 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.95 \mathrm { hrs }\)
• B) \(5.78 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 17.02 \mathrm { hrs }\)
• C) \(5.92 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.88 \mathrm { hrs }\)
• D)\(6.08 \mathrm { hrs } < \mu _ { 1 } - \mu _ { 2 } < 16.72 \mathrm { hrs }\)

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Definitions:

Tardiness

The act of being late or delaying arrival beyond the expected or scheduled time, often viewed negatively in professional and educational settings.

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Job Design Strategy

The process of defining how work will be performed and what tasks will be required in a given job.