Verified step by step guidance
05:45
04:39
05:53Using the Empirical Rule In Exercises 29–34, use the Empirical Rule.
Use the sample statistics from Exercise 29 and assume the number of vehicles in the sample is 75.
a. Estimate the number of vehicles whose speeds are between 63 miles per hour and 71 miles per hour.
Protein Powder During a quality assurance check, the actual contents (in grams) of six containers of protein powder were recorded as 1525, 1526, 1502, 1516, 1529, and 1511.
a. Find the mean and the median of the contents.
Pearson’s Index of Skewness The English statistician Karl Pearson (1857–1936) introduced a formula for the skewness of a distribution.
P = 3 (x̄ - median) / s
Most distributions have an index of skewness between -3 and 3. When P > 0, the data are skewed right. When P < 0, the data are skewed left. When P = 0, the data are symmetric. Calculate the coefficient of skewness for each distribution. Describe the shape of each.
a. x̄ = 17, s = 2.3, median = 19
Extending Concepts
Data Analysis Students in an experimental psychology class did research on depression as a sign of stress. A test was administered to a sample of 30 students. The scores are shown in the table at the left.
" style="" width="275">
a. Find the mean and the median of the data.
Shifting Data Sample annual salaries (in thousands of dollars) for employees at a company are listed.
40 35 49 53 38 39 40
37 49 34 38 43 47 35
a. Find the sample mean and the sample standard deviation.
Drawing a Box-and-Whisker Plot In Exercises 15–18,
(a) find the five-number summary
4 7 7 5 2 9 7 6 8 5 8 4 1 5 2 8 7 6 6 9
