In Testing Whether the Means of Two Normal Populations Are $n _ { 1 } = 20$

question 35

Multiple Choice

In testing whether the means of two normal populations are equal, summary statistics computed for two independent samples are as follows: $n _ { 1 } = 20$ , $\bar { x } _ { 1 } = 10.8$ , $s _ { 1 } = 0.90$ . $n _ { 2 } = 18$ , $\bar { x } _ { 2 } = 9.6$ , $s _ { 2 } = 1.10$ . Assume that the population variances are unequal. The standard error of the sampling distribution of the sample mean difference $\bar { x } _ { 1 } - \bar { x } _ { 2 }$ is equal to:

• A) 0.3247.
• B) 0.3282.
• C) 0.1054.
• D) 0.1125.

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Definitions:

Spinal Cord

A long, thin, tubular structure made up of nervous tissue, extending from the brainstem down the vertebral column, playing a critical role in transmitting neural signals between the brain and the rest of the body.

Pyramids

Structures in the medulla oblongata of the brain involved in the transmission of motor signals to the spinal cord.

Descending Tracts

These are pathways in the central nervous system that transmit motor signals from the brain down the spinal cord to the muscles or glands.

Ascending Tracts

Ascending Tracts refer to the pathways in the nervous system through which sensory information from the peripheral nerves is conveyed up to the brain.