Two Independent Samples of Sizes 20 and 30 Are Randomly

question 136

Multiple Choice

Two independent samples of sizes 20 and 30 are randomly selected from two normally distributed populations. Assume that the population variances are unknown but equal. In order to test the difference between the population means, , the sampling distribution of the sample mean difference, , is:

• A)normal.
• B)Student -t with 50 degrees of freedom.
• C)Student -t with 48 degrees of freedom.
• D)None of these choices.

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Definitions:

Positive Differences

The result obtained when subtracting a smaller number from a larger number in each pair of a data set.

Negative Differences

Refers to the results obtained when subtracting a number from another number that is smaller, resulting in a negative value.

Significance Level

A threshold within statistical hypothesis testing that measures the probability of rejecting a true null hypothesis, typically denoted by alpha (α).

Location

Refers to the specific position or area where something is situated or occurs.