Find z such that 99 of the area under the standard normal cu

Find z such that 99% of the area under the standard normal curve lies between -z and z

Solution

As 99% of the area is between them, then only 1% is at the extremes.

Thus, the left tailed area of -z is 0.01/2 = 0.005.

Thus, by table or technology,

-z = -2.575829304

Thus,

z = 2.575829304 [ANSWER]