Exam 3: Displaying and Summarizing Quantitative Data

The following stem-and-leaf display shows the number of homeless cats and dogs that had to be euthanized each year in a large city for the period 1985-2004. Key: 87 | 5 = 87,500 cats and dogs euthanized

John liked to order the all-you-can-eat shrimp at his favorite restaurant.Here are the number of shrimp he ate during his last five visits to the restaurant. 15,16,13,15,10

A store manager kept track of the number of newspapers sold each week.The results are shown below.

Here are summary statistics of the four last digits of social security number of 500 customers,corresponding to the following histogram. Is the mean or median a "better" summary of the centre of the distribution?

Here are the number of hours that Bill has exercised each week since he started keeping records. Round your answer to the nearest tenth.

A small company employs a supervisor at $1,400 a week,an inventory manager at $800 a week,8 stock boys at $300 a week each,and 6 drivers at $700 a week each.

The diastolic blood pressures,in mm Hg,for a sample of patients at a clinic are given.Create a stem-and-leaf display of the data.Do not use split stems.

The histogram shows the sizes (in acres)of 169 farms in Ontario.In addition to describing the distribution,approximate the percentage of farms that are under 100 acres.

The weights,in kilograms,of 17 randomly selected adults are given below.Find the interquartile range (IQR)by hand.

Here are the average mathematics achievement scores for ninth graders in 34 counties.Find the standard deviation.

A sewing supply company has a database of tens of thousands of products that they sell in their stores.One of the variables in the database,Thread_Colour,contains the names of the colors of the various spools of thread that are sold.The most commonly sold are white,black,and brown,but there are also magenta,azure,sea foam green,and nutmeg,to name a few others.In all there are more that 500 different colours,each with a corresponding numeric code.Here are a few of them: An intern who was asked to analyze the company's thread sales presented these summary statistics for the variable Thread_Colour: a)What does the mean of 35.89 mean? b)What are the typical reasons that cause measures of centre and spread to be as different as those in this table? c)Is that why these are so different?

A business owner recorded her annual profits for the first 12 years since opening her business.The stem-and-leaf display below shows the annual profits in thousands of dollars. Key: 13 | 8 = $138,000 profit

A student at a local university took a total of 20 exams during freshman year.The student recorded the exam scores as percentages and created the following stem-and-leaf display.The lower stem contains leaves with the digits 0-4 and the upper stem contains leaves with digits 5-9.In addition to describing the distribution,give a reason to account for the shape of this distribution. Key: 9 | 3 = 93%

Ontario wanted to find the typical size of farms in the province.The data below shows the sizes (in acres)of the 84 farms located in Ontario.Create a histogram of the data using bins that are 50 acres wide.

The number of days off that 30 police officers took in a given year are provided below.Create a histogram of the data using bins 2 days wide.

Ages of patients who had their tonsils removed at a hospital over the course of a year.

Three statistics classes (50 students each)took the same test.Shown below are histograms of the scores for the classes.Use the histograms to answer the question. -Which class had the smallest IQR?

Which class do you think performed better on the test?

A new business had the following monthly revenues,in dollars.

Here is the stem-and-leaf display of the midterm test scores for the seventh-period typing class. Would you use the median or the mean to describe the centre of this distribution?