Consider the Following to Answer the Question(s) Below

question 23

Multiple Choice

Consider the following to answer the question(s) below:
A consumer group was interested in comparing the operating time of cordless toothbrushes manufactured by two different companies. They took a random sample of 18 toothbrushes from Company A and 15 from Company B. Each was charged overnight and the number of hours of use before needing to be recharged was recorded. Company A toothbrushes operated for an average of 119.7 hours with a standard deviation of 1.74 hours; Company B toothbrushes operated for an average of 120.6 hours with a standard deviation of 1.72 hours. Do these samples indicate that Company B toothbrushes operate more hours on average than Company A toothbrushes?
-Suppose that we test the hypotheses (assuming Company A is group 1 and Company B is group 2) : H0 : µ1 - µ2 = 0 vs. HA : µ1 - µ2 ≠ 0. Provided that the P-value is greater than α = 0.05, we fail to reject the null hypothesis. If we want to construct a 95% confidence interval for the difference between the mean operating times of cordless toothbrushes of Company A and Company B, we will expect

• A) both the upper and lower limits be negative.
• B) both the upper and lower limits to be positive.
• C) that zero is not included in the interval.
• D) that zero falls into the interval.
• E) both the upper and lower limits be positive and fairly high.

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Definitions:

Estimated Activity Volume

The projected amount of activity or production, measured in units, hours, or any other quantifiable terms, expected for a certain period.

Activity Cost Pool

A “bucket” in which costs are accumulated that relate to a single activity measure in an activity-based costing system.

Plantwide Overhead Rate

A single predetermined overhead rate that is used throughout a plant.