Scores on a Test Are Normally Distributed with a Mean

question 154

Multiple Choice

Scores on a test are normally distributed with a mean of 68.2 and a standard deviation of 10.4. Estimate the probability that among 75 randomly selected students, at least 20 of them score greater than 78.

• A) 0.1736
• B) 0.0113
• C) 0.0166
• D) 0.0239

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Definitions:

Hindsight Bias

The tendency to believe, after an event has occurred, that one would have predicted or expected the outcome, also known as the "knew-it-all-along" effect.

Confounding Variable

An external factor in a research study that correlates with both the dependent and independent variables, potentially skewing results.

Alcoholic Beverage

A drink that contains ethanol, commonly known as alcohol, which is a psychoactive substance.

Control Group

In experimental research, the group that does not receive the treatment or intervention being tested, serving as a baseline for comparison.