Reference no: EM132464039

Problem: The following data sets are normally distributed:

a) GRE (Graduate Record Exam) individual test scores:

mean= 530 , standard deviation= 128

b) Stanford-Binet IQ scores:

mean= 100 , standard deviation= 15

c) lengths of pregnancies:

mean= 266 days , standard deviation= 16 days

1. Find the width of the interval that spans the middle 70% of each distribution.

2. Find the cutoff for the top 12% of each distribution.

3. a) Find the percent of GRE scores that fall between 278 and 688.

b) Find the percent of pregnancies that last between 248 and 284 days.

c) Find the percent of IQ scores that fall between 117 and 121.