Construct a Confidence Interval For $\mu _ { \mathrm { d } }$

question 160

Multiple Choice

Construct a confidence interval for $\mu _ { \mathrm { d } }$ , the mean of the differences d for the population of paired data. Assume that the
population of paired differences is normally distributed.
-A test of abstract reasoning is given to a random sample of students before and after they completed a formal logic course. The results are given below. Construct a 95% confidence interval for the mean difference between
The before and after scores.

• A) \(0.2 < \mu _ { \mathrm { d } } < 7.2\)
• B) \(1.2 < \mu _ { \mathrm { d } } < 5.7\)
• C) \(0.8 < \mu _ { \mathrm { d } } < 6.6\)
• D) \(1.0 < \mu _ { \mathrm { d } } < 6.4\)

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Definitions:

Average Amount

The mean value obtained by dividing the sum of all values by the number of values.

Weighted Average Delay

A calculation used to find the average delay in time or process, taking into account the weight or importance of different delays.

Collection Delay

The period between when a bill is issued or an invoice is sent and when the payment is actually received.

Average Amount

This term refers to the mean value or central tendency of a set of numerical values, calculated as the sum of the values divided by the number of values.