Exam 3: Statistical Description of Data

Which of the following statements are true for the following data values: 9,7,8,6,9,10,and 14?

The average order size for a home shopping company follows a bell-shaped and symmetrical distribution has a mean equal to $75 and a standard deviation equal to $10.What range of sales order size would we expect to see 95 percent of the time?

Salaries The salaries (in thousands of dollars)for a sample of 13 employees of a firm are: 26.5,23.5,29.7,24.8,21.1,24.3,20.4,22.7,27.2,23.7,24.1,24.8,and 28.2. -Compute the variance of the salaries.

The average score for a class of 25 students was 75.If the 15 female students in the class averaged 70,then the male students in the class averaged:

The average profit per unit for Product A is $5.32,Product B is $7.98,and Product C is $9.69.If the percentages of each sold are 36,29,and 35 respectively,what is the weighted mean profit per unit?

Variables A sample of eight observations of variables x and y is shown below: x 5 3 7 9 2 4 6 8 y 20 23 15 11 27 21 17 14 -Calculate the coefficient of correlation r and comment on the relationship between x and y. r = ____________________. Comments:

The mean of a set of values describes the 50th percentile.

In a test of a lifelong brand of tires,a survey revealed that the mean life was 35,000 miles and the standard deviation was 7,083 miles.If the shape of the population distribution is not known,approximately what percentage of the tires last less than 20,834 miles?

Compute the sample mean and sample standard deviation from the following set of grouped data: 0 8 1 10 2 12 3 9 4 1 $\bar { x }$ = ____________________. s = ____________________.

Heidi has been keeping track of what she spends to eat out.The last week's expenditures (in dollars)for meals eaten out were 3.69,3.95,4.19,8.91,5.49,12.53,and 5.66.Calculate the mean amount she spent on meals last week.

Use Minitab or Excel to produce the scatter diagram that includes the best-fit linear equation.

The midrange is the average of the two middle data values.

Consider the following sample data: 4,14,6,9,21,3,7,and 10. Calculate the median.

A data sample has a mean of 107,a median of 122,and a mode of 134.What type of distribution does it have? Why?

Percentiles divide the values into 100 parts of equal size,each comprising 1% of the observations.

The ____________________ is a graphical device that simultaneously displays several of the measures of central tendency and dispersion.

Texas Department A monthly report to the Texas Department of Health,division of Water Hygiene,contained the following water production data in thousands of gallons: 5263 5636 5264 4395 6090 5293 4668 5725 5171 4378 5118 5538 4838 5167 5119 5438 6843 5262 4653 5303 5913 4570 5142 5964 6431 4719 5358 6043 4554 5805 -What is the quartile deviation?

Consider the following sample data: 4,14,6,9,21,3,7,and 10. Calculate the mean.

Data set A: 14,11,15,12,and 13. Data set B: 13,8,20,6,and 18. Which data set has the larger standard deviation,A or B?

Which of the following is not a measure of dispersion?