A Researcher Gives IQ Tests to a Large Group of Adults

question 82

Multiple Choice

A researcher gives IQ tests to a large group of adults, and discovers that the
mean, median and mode all equal 100. The highest score in the group was 130
and the lowest was 70. Between IQ's of 75 and 125, 80% of the group was found, and 50% were found between IQ's of 90 and 110. The shape of the graphed distribution was mesokurtic.
-The interdecile range was equal to

• A) 60
• B) 50
• C) 20
• D) 0

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Definitions:

Normal Distribution

A probability distribution that is symmetric about the mean, depicting that data near the mean are more frequent in occurrence than data far from the mean.

Binomial Distribution

A probability distribution that models the number of successes in a fixed number of independent Bernoulli trials with the same probability of success.

F-distribution

A probability distribution that arises in the analysis of variance and is used to calculate whether two observed variances are significantly different.

Matched Pairs

A study design where subjects are paired based on certain criteria, ensuring that each pair is similar except for the treatment given.