Unit Test — Unit test Answers

In a certain breed of cattle, the length of gestation has a mean of 284 days and a standard deviation is 5.5 days. What is the z-score for a gestation period that lasts 290 days?

Keeping car tires inflated is essential to safe driving. For one type of car tire, the tire pressure in pounds per square inch (psi) is assumed to be approximately Normal, with a mean of 35 psi and a standard deviation of 2 psi. What percentage of tires are inflated to a pressure above 36 psi?Find the z-table here.

Scores on a national math test are Normally distributed, with a mean score of 490 and a standard deviation of 50. Which test score represents the top 20%, rounded to the nearest whole number?Find the z-table here.

Consider the given density curve.