Question

In: Statistics and Probability

Suppose that X is normally distributed with a mean of 50 and a standard deviation of...

Suppose that X is normally distributed with a mean of 50 and a standard deviation of 12. What is P(X ≥ 74.96)

a) 0.481

b) 0.019

c) 0.981

d) 0.024

e) 0.020

f) None of the above

Solutions

Expert Solution

Solution:

Given: X is normally distributed with a mean of 50 and a standard deviation of 12.

That is: X ~ Normal

We have to find: =........?

Find z score:

thus we get:

Look in z table for z = 2.0 and 0.08 and find area.

P( Z< 2.08)= 0.9812

Thus

( Rounded to 3 decimal places.)

Thus correct option is b) 0.019


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