SOLUTION: Intelligence quotients on the Stanford binet intelligence test are normally distributed with a mean of 100 and a standard deviation of 16. Use the 68-95-99.7 rule to find the perce

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Question 926296: Intelligence quotients on the Stanford binet intelligence test are normally distributed with a mean of 100 and a standard deviation of 16. Use the 68-95-99.7 rule to find the percentage of people with IQs
a)between 68 and 132
b)between 68 and 100
c)above 116
d)below 68
e)above 148
Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website!
For the normal distribution: Below: z = 0, z = � 1, z= �2 , z= �3 are plotted.
Area under the standard normal curve to the left of the particular z is P(z)
Note: z = 0 (x value: the mean) 50% of the area under the curve is to the left and 50% to the right

......
one standard deviation from the mean accounts for about 68% of the set
two standard deviations from the mean account for about 95%
and three standard deviations from the mean account for about 99.7%.
.......
mean of 100 and a standard deviation of 16
a)between 68 and 132: (2SDs on either side of mean) 95%
b)between 68(-2SDs) and 100: 50% - 95%/2
c)above 116 (1SD): 50% + 68%/2
d)below 68(-2SDs): (100%-95%)/2
e)above 148 (3Sds): (100%-99.7%)/2