2.5 Percentiles and z-Scores

In Exercises 1 – 4, use the ogive, which represents the cumulative frequency distribution for quantitative reasoning scores on the Graduate Record Examination in a recent range of years. (Adapted from Educational Testing Service)

What score represents the 70^th percentile? How should you interpret this?

In Exercises 1 – 4, use the ogive, which represents the cumulative frequency distribution for quantitative reasoning scores on the Graduate Record Examination in a recent range of years. (Adapted from Educational Testing Service)

Which score represents the 40^th percentile? How should you interpret this?

In Exercises 1 – 4, use the ogive, which represents the cumulative frequency distribution for quantitative reasoning scores on the Graduate Record Examination in a recent range of years. (Adapted from Educational Testing Service)

What percentile is a score of 140? How should you interpret this?

In Exercises 1 – 4, use the ogive, which represents the cumulative frequency distribution for quantitative reasoning scores on the Graduate Record Examination in a recent range of years. (Adapted from Educational Testing Service)

What percentile is a score of 170? How should you interpret this?

In Exercises 5 – 7, use the data set, which represents wait times (in minutes) for various services at a state’s Department of Motor Vehicles locations.

Which wait time represents the 50^th percentile?

In Exercises 5 – 7, use the data set, which represents wait times (in minutes) for various services at a state’s Department of Motor Vehicles locations.

Find the percentile that corresponds to a wait time of 20 minutes.

In Exercises 5 – 7, use the data set, which represents wait times (in minutes) for various services at a state’s Department of Motor Vehicles locations.

Which wait times are between the 25^th and 75^th percentiles?

The distribution of the ages of the winners of the Tour de France from 1903 to 2016 is approximately bell-shaped. The mean age is 27.9 years, with a standard deviation of 3.3 years. In Exercises 8 – 10, use the corresponding z-score to determine whether the age is unusual. Explain your reasoning. (Source:  Le Tour de France)

Winner:  Jan Ullrich           Age: 24

The distribution of the ages of the winners of the Tour de France from 1903 to 2016 is approximately bell-shaped. The mean age is 27.9 years, with a standard deviation of 3.3 years. In Exercises 8 – 10, use the corresponding z-score to determine whether the age is unusual. Explain your reasoning. (Source:  Le Tour de France)

Winner:  Firmin Lambot           Age: 36

The distribution of the ages of the winners of the Tour de France from 1903 to 2016 is approximately bell-shaped. The mean age is 27.9 years, with a standard deviation of 3.3 years. In Exercises 8 – 10, use the corresponding z-score to determine whether the age is unusual. Explain your reasoning. (Source:  Le Tour de France)

Winner:  Christopher Froome           Age: 28