Answer: About 99.7% IQ scores falls within 43 and 157.
Explanation:
According to the empirical rule , if a data follows normal distribution then about 99.7% of the population lies with in three standard deviations from mean.
Given: IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 19.
Since , the graph of normal distribution is bell-shaped , it mean that IQ scores follow normal distribution.
Then, About 99.7% IQ scores falls within Mean ± 3 (Standard deviation).
i.e. About 99.7% IQ scores falls within 100± 3(19).
i.e. About 99.7% IQ scores falls within 100- 57 and 100+57.
i.e. About 99.7% IQ scores falls within 43 and 157.
Therefore , by empirical rule
About 99.7% IQ scores falls within 43 and 157.