If Two Random Samples of Sizes $n _ { 1 }$

question 9

Short Answer

If two random samples of sizes $n _ { 1 }$ and $n _ { 2 }$ are selected independently from two populations with means $\mu _ { 1 }$ and $\mu _ { 2 }$ , then the mean of the sampling distribution of the sample mean difference, $\bar { X } _ { 1 } - \bar { X } _ { 2 }$ , equals: $$\begin{array} { | l | l | } \hline \text { A. } & \mu _ { 1 } + \mu _ { 2 } . \\\hline \text { B. } & \mu _ { 1 } - \mu _ { 2 } \\\hline \text { C. } & \mu _ { 1 } / \mu _ { 2 } \\\hline \text { D. } & \mu _ { 1 } \mu _ { 2 } \\\hline\end{array}$$ :

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Definitions:

Bond Funds

Mutual funds that invest primarily in bonds or other types of debt securities.

Standard Deviation

An analysis tool for the variation or dispersal range within a collection of figures.

Population Mean

The average value of a set of characteristics for the entire population, calculated as the sum of all values divided by the number of values.

Level of Confidence

The degree of certainty or trust one can have in the interval estimate of a population parameter.