Statistics: Unit 5 Lesson 2 Topic 1 Practice

When Dylan commutes to work, the amount of time it takes him to arrive is normally distributed with a mean of 42 minutes and a standard deviation of 2.5 minutes. Out of the 260 days that Dylan commutes to work per year, how many times would his commute be shorter than 42 minutes, to the nearest whole number?

130

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Out of a randomly selected 2700 people from the population, how many of them would have an IQ between 86 and 109, to the nearest whole number?

1486

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. What percentage of people have an IQ score less than 117, to the nearest tenth?

87.1%

When Ximena commutes to work, the amount of time it takes her to arrive is normally distributed with a mean of 38 minutes and a standard deviation of 4.5 minutes. Using the empirical rule, determine the interval that represents the middle 68% of her commute times.

(33.5, 42.5)

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Using the empirical rule, determine the interval that would represent the middle 95% of IQ scores.

(70, 130)

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability that a randomly chosen person's IQ score will be between 82 and 117, to the nearest thousandth?

0.756

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Out of a randomly selected 3100 people from the population, how many of them would have an IQ less than 133, to the nearest whole number?

3057

The weight of oranges growing in an orchard is normally distributed with a mean weight of 7 oz. and a standard deviation of 1.5 oz. From a batch of 1600 oranges, how many would be expected to weight more than 8 oz., to the nearest whole number?

404

In an all boys school, the heights of the student body are normally distributed with a mean of 70 inches and a standard deviation of 3 inches. What percentage of the students are shorter than 74 inches tall, to the nearest tenth?

90.9%

At a customer service call center for a large company, the number of calls received per hour is normally distributed with a mean of 130 calls and a standard deviation of 10 calls. What is the probability that during a given hour of the day there will be less than 129 calls, to the nearest thousandth?

0.460

At a customer service call center for a large company, the number of calls received per hour is normally distributed with a mean of 90 calls and a standard deviation of 20 calls. What is the probability that during a given hour of the day there will be between 91 calls and 134 calls, to the nearest thousandth?

0.466

When Ava commutes to work, the amount of time it takes her to arrive is normally distributed with a mean of 51 minutes and a standard deviation of 4.5 minutes. What is the probability that on a given day, her commute will be longer than 46 minutes, to the nearest thousandth?

0.867

The amount of time a certain brand of light bulb lasts is normally distribued with a mean of 1500 hours and a standard deviation of 90 hours. Out of 165 freshly installed light bulbs in a new large building, how many would be expected to last more than 1640 hours, to the nearest whole number?

10

When Angel commutes to work, the amount of time it takes him to arrive is normally distributed with a mean of 37 minutes and a standard deviation of 3 minutes. Out of the 216 days that Angel commutes to work per year, how many times would his commute be between 31 and 45 minutes, to the nearest whole number?

210

When Parker goes bowling, his scores are normally distributed with a mean of 150 and a standard deviation of 12. Out of the 70 games that he bowled last year, how many of them would he be expected to score less than 172, to the nearest whole number?

68

At a local restaurant, the amount of time that customers have to wait for their food is normally distributed with a mean of 24 minutes and a standard deviation of 3 minutes. If you visit that restaurant 46 times this year, what is the expected number of times that you would expect to wait longer than 27 minutes, to the nearest whole number?

7

For males in a certain town, the systolic blood pressure is normally distributed with a mean of 110 and a standard deviation of 5. What percentage of males in the town that have a systolic blood pressure higher than 105, to the nearest tenth?

84.1%

When Tariq goes bowling, his scores are normally distributed with a mean of 110 and a standard deviation of 10. Using the empirical rule, what percentage of the games that Tariq bowls does he score between 80 and 140?

99.7%