A Random Variable Is Normally Distributed with a Mean of 25

question 26

Multiple Choice

A random variable is normally distributed with a mean of 25 and a standard deviation of 5. If an observation is randomly selected from the distribution, determine two values of which the smallest has 25% of the values below it and the largest has 25% of the values above it.

• A) 18.85 and 27.94
• B) 19.31 and 21.12
• C) 16.23 and 18.82
• D) 21.65 and 28.35

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Definitions:

Confidence Interval

An interval of figures obtained from statistics of a sample, expected to include the value of a hidden population parameter.

Level of Significance

A predetermined value that indicates the probability of rejecting a true null hypothesis in hypothesis testing.

Chi-Squared Variable

A variable that follows the chi-squared distribution, typically used in tests of independence and goodness-of-fit.

Degrees of Freedom

The sum of independent quantities or values able to be set for a statistical distribution.