Exam 30: Representing and Interpreting Data With One Variable

The standard deviations for the test scores for two classes are quite different (on the same test). What does that tell you?

A circle graph (pie chart) can be used with categorical data.

A) Make a box plot for the exam scores. B) Give the five-number summary for the scores. C) What is the 90th percentile for these scores? D) Are there any outliers? E) Make a stem-and-leaf plot for the test scores. F) Make a histogram for the test scores. Use a cell width of 5 points. Exam scores Exam scores, ordered 25 81 65 78 64 77 46 75 38 70 58 68 44 68 65 67 60 66 50 66 70 65 55 65 44 64 68 62 67 60 66 59 66 58 81 55 68 53 51 51 51 51 75 50 53 49 47 47 62 46 59 44 32 44 78 38 49 32 77 25

A particular medicine is not effective if there is less than 147 milligrams of Xylz in a dose, and the medicine is dangerous if there is more than 153 milligrams of Xylz in a dose. One manufacturer of the medicine uses a process that gives medicine with a normally distributed strength of Xylz, with mean 150 milligrams and standard deviation 1.5 milligrams of Xylz per dose. Approximately what percent of the manufacturer's total production will be thrown out and not used because of effectiveness or safety reasons?

Suppose that the class mean on a test is 81.2%. What does the 81.2% mean (not how it was calculated)?

The median, rather than the mean or mode, is often given in reports about house prices. Why is that?

Calculate the standard deviation for these scores: 80, 72, 80, and 88. Show your work for credit.

Of the 1000 scores on a test, 250 scores will be in the second and third quartiles.

Make a box-and-whiskers plot for these 24 scores, and give the five-number summary. 20, 19, 19, 18, 21, 20, 20, 17, 19, 21, 21, 19, 22, 18, 21, 19, 18, 22, 18, 19, 21, 21, 19, 20 Tell what each number in the five-number summary represents.

Box-and-whiskers plots for a sample of students and their number of hours of sleep per night during the week are given below. (Data adapted from DataScope.) A) Why is the one dot for a male student separate from the rest of the graph? B) How many female students sleep more than 11 hours? C) How many male students sleep between 10 and 10.75 hours? D) Do any females sleep longer than all the males? Explain. E) Give the interquartile range for the males. F) Give the five-number summary for the females. G) If the female and male data were put together, what would be the median number of hours of sleep? Explain how you know or why you can't tell.

Make a bar graph for the following data about favorite color. Use as much of the grid as you need, but do not add any squares. Be sure to give all labels. Blue: 18 students Red: 12 students Green: 6 students Orange: 4 students

The mean is affected more by an extreme value than the median is.