Normal Probability Z Table

A factory produces light bulbs with a mean lifespan of 1200 hours and a standard deviation of 100 hours. What is the probability that a randomly selected light bulb will last more than 1250 hours? Use the standard normal table to find the probability.

• 0.1056

• 0.3085

• 0.1915

• 0.0668

A standardized test has a mean score of 500 and a standard deviation of 80. What is the probability that a randomly selected student scores between 480 and 520?

• 0.1974

• 0.3085

• 0.2417

• 0.3829

The average height of adult males in a certain country is 175 cm with a standard deviation of 10 cm. What is the probability that a randomly selected adult male is shorter than 160 cm?

• 0.0668

• 0.1587

• 0.8413

• 0.9772

The average weight of a newborn baby is 3.5 kg with a standard deviation of 0.5 kg. What is the probability that a randomly selected newborn weighs between 3 kg and 4 kg?

• 0.6826

• 0.9544

• 0.3413

• 0.1359

What is the probability that a score is under (left of) -.37?

• .6443

• .3974

• .3557

• .3156

• 15.87%

• 15.39%

• 9.68%

• 84.61%

In a normal distribution find the probability Z > 1.3

• .0227

• .0698

• .0968

• .9032

• 92.22%

• .9222%

• 92.07%

• .9207%

What is the probability that a score is under (left of) 1.73?

• .9484

• .9664

• .9573

• .9582

What is the probability that a score is under (left of) .73?

• .7357

• .7673

• .7389

• .7967