Finding Areas within a Normal Distribution — Unit test Answers

Heights of four-year olds are Normally distributed, with a mean of 40 inches and a standard deviation of 3 inches. At her four-year checkup, Hannah's height measures in the 99th percentile. How tall is Hannah?Find the z-table here.

In the standard Normal distribution, 43% of observations lie below which z-score?Find the z-table here.

The times for running a 5K for a local charity event are Normally distributed. Which standardized time represents the 87th percentile?Find the z-table here.

Scores on a national English test are Normally distributed, with a mean score of 510 and a standard deviation of 75. Jaxon’s test score is in the 85th percentile. What is his test score, rounded to the nearest whole number?Find the z-table here.

Heights of four-year-olds are Normally distributed, with a mean of 40 inches and a standard deviation of 3 inches. At his four-year checkup, Marlon’s height is measured as taller than 70% of boys his age. How tall is Marlon?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.

The salt content in snack bags of pretzels is Normally distributed, with a mean of 180 mg and a standard deviation of 15 mg. Eighty four percent of bags have a salt content higher than which value?Find the z-table here.

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 length of gestation, rounded to the nearest whole number, represents the 18th percentile?Find the z-table here.

Scores on a national English test are Normally distributed, with a mean score of 510 and a standard deviation of 75. Sixty-eight percent of English tests were less than which score, rounded to the nearest whole number?Find the z-table here.

The times for running a 5K for a local charity event are Normally distributed, with a mean time of 28 minutes and standard deviation of 5.4 minutes. Which time represents the 60th percentile?Find the z-table here.