IQ Scores Are Normally Distributed, with a Mean of 100

question 13

Multiple Choice

IQ scores are normally distributed, with a mean of 100 and a standard deviation of 15. Approximately what percentage of people have IQ scores that fall below 70?

• A)2%
• B)5%
• C)34%
• D)64%

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Definitions:

Diorite

A medium- to coarse-grained, intermediate-composition igneous rock; the phaneritic equivalent of andesite.

Dissolved Gas

A gas that has been absorbed into a liquid solution, such as carbon dioxide in water, often influencing chemical reactions and physical properties.

Andesite

A volcanic rock type that is intermediate in composition between basalt and rhyolite, often found in volcanic arcs associated with convergent tectonic boundaries.

Alpha Decay

The radioactive decay process in which an unstable atom fissions, releasing a positively charged particle with two protons and two neutrons.