Abag containing 20 blue marbles, 20 white marbles, and 1 red marble

Step-by-step explanation:

The Standard Deviation Rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below

68% of data falls within the first standard deviation from the mean.

95% fall within two standard deviations.

99.7% fall within three standard deviations.

The distribution of the IQ (Intelligence Quotient) is approximately normal in shape with a mean of 100 and a standard deviation of 15.

Therefore, the range of IQ scores that many (68%) people have is between

100 - 15 and 100 + 15

It becomes

85 to 115