The Expected Value of the Difference of Two Sample Means

question 6

Multiple Choice

The expected value of the difference of two sample means equals the difference of the corresponding population means:

• A) only if the populations are normally distributed.
• B) only if the samples are independent.
• C) only if the populations are approximately normal and the sample sizes are large.
• D) All of these choices are correct.

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Definitions:

Mass Extinctions

Significant global events in the Earth's history where large percentages of species die out in a relatively short period of time, often due to catastrophic environmental changes.

Geologic Timescale

A method of dating based on the chronological correlation of Earth's geological layers to time, utilized by geologists for depicting the sequence and association of historical events on Earth.

Seafloor Spreading

The process by which new oceanic crust is formed at mid-ocean ridges and slowly moves away from them.

Isotopic Ages

The determination of the age of rocks, minerals, or samples by measuring the relative abundance of specific isotopes.