Two Independent Samples of Sizes 35 and 40 Are Randomly $\mu _ { 1 } - \mu _ { 2 }$

question 9

Multiple Choice

Two independent samples of sizes 35 and 40 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, $\mu _ { 1 } - \mu _ { 2 }$ , the sampling distribution of the sample mean difference, $\bar { x } _ { 1 } - \bar { x } _ { 2 }$ , is:

• A) normally distributed.
• B) t-distributed with 75 degrees of freedom.
• C) t-distributed with 73 degrees of freedom.
• D) F-distributed with 34 and 39 degrees of freedom.

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Definitions:

Grazing Varieties

Types or breeds of animals or plants that are particularly suited or used for grazing, affecting ecosystems and agricultural practices.

Observational Study

A study where the researcher observes and records behavior or outcomes without manipulating any variables.

Supermarket Chains

Refers to large retail entities that operate multiple stores under the same brand or ownership, specializing in selling a wide variety of groceries and household products.

Average Prices

The sum of the prices of all items in a set divided by the number of items, used to give a central value of the dataset.