Question

Suppose a normal distribution has a mean of 98 and a standard deviation of 6. What is P(x< or = to 110)

Answer 1

0.975

Explanation:

A P E X

Answer 2

97.8%

Explanation:

110 is 2 standard deviations above the mean (6+6 = 12)

12+98 = 110

Looking at the standard deviation curve

P(x< or = to 110) = 1 - P(x>110)

We can find the probability that x>100 by adding anything above 2 standard deviations above the curve.

P(x>110) = 2.1+.1 = 2.2%

P(x< or = to 110) = 1 - P(x>110)

= 1- 2.2%

= 1- .022

= .978

= 97.8 %