Chapter 2 quiz- Statistics

Data was collected on the monthly seasonally adjusted civilian unemployment rate for a country over a​ 10-year period. Which of the following is the best for presenting the​ data?

A. A​ time-series plot

The graph to the right represents the expenditures of a company. ​(a) How is the graph ​misleading? b) What could be done to improve the​ graphic?

(a) It looks twice as much money is spent on wages than products (b) The lengths of the bars should be proportional to the percentages.

The ages of the voters at a poll during a​ 20-minute period are listed below. Use five classes with a uniform width of 10​ years, where the lower limit of the first class is 20 years. Construct the specified histogram. ​35, 29,​ 48, 63,​ 64, 38,​ 21, 23,​ 41, 68,​ 61, 42,​ 43, 47,​ 33, 37,​ 46, 27,​ 23, 30

20-29 = 5 30-39 = 5 40-49 = 6 50-59 = 0 60-69 = 4

The data to the right represent the number of grams of fat in breakfast meals offered at a certain restaurant. Construct a​ stem-and-leaf plot and describe the shape of the distribution.

A Skewed right

A type of vertical bar chart in which the categories are plotted in the descending rank order of the magnitude of their frequencies is called which of the​ following?

A Pareto chart

A survey of 150 executives were asked what they think is the most common mistake candidates make during job interviews. Six different mistakes were given. Which of the following is the best for presenting the​ information?

A bar chart

A library took a survey to find the age distribution of 50 randomly selected new youth members. The results are shown in the table below. Age Group ​3-5 ​6-8 ​9-11 ​12-14 ​15-17 Number of New Members 4 7 17 15 7

Age Group Relative Frequency ​3-5: .08 ​6-8: .14 ​9-11: .34 ​12-14: .3 ​15-17: .14 ​(b) What percentage of new youth members are in the 34% (c) What percentage of the new youth members are age 12 or older12 or older​? 44%

The data to the right represent the number of grams of fat in breakfast meals offered at a certain restaurant. Construct a​ stem-and-leaf plot and describe the shape of the distribution. distribution. 25 5 2 42 8 16 17 16 2 14 27 28 2 14 7 54 31 35 37 28 11 12 49 6 Construct a​ stem-and-leaf plot. Choose the correct answer below.

B Skewed right

Determine whether the following statement is true or false. The shape of the distribution shown is best classified as skewed left.

False

Determine whether the following statement is true or false. ​Stem-and-leaf plots are particularly useful for large sets of data.

False

What is the difference between a bar chart and a​ histogram?

The bars on a bar chart do not touch while the bars of a histogram do touch.

The safety manager at Bumbler Enterprises provides the graph shown on the right to the plant manager and claims that the rate of worker injuries has been reduced by 50​% over a​ 12-year period. Does the graph support his​ claim? Explain.

The graph does not support his claim. The vertical scale does not start at 0 which distorts the percent of change.

Explain what is misleading about the graphic. A time-series plot titled "Annual Sales of Widgets at Company X" has a horizontal axis labeled from less than 2004 to 2012 in increments of 2 and a vertical axis labeled "Number of Widgets Sold" from 10000 to 35000 in increments of 5000. The following 10 points are plotted and connected from left to right by line segments: (2003, 11000); (2004, 13000); (2005, 17000); (2006, 18000); (2007, 20000); (2008, 22000); (2009, 25000); (2010, 27000); (2011, 29000); (2012, 32000). All coordinates are approximate. 2004 2006 2008 2010 2012

The vertical scale does not begin at zero.

A categorical variable has three​ categories, with the frequencies of occurrence below. a. Compute the percentage of values in each category. b. What conclusions can you reach concerning the​ categories? Category: A B C Frequency: 27 9 14

a. 54% 18% 28% b. Category Upper A occurs more than half of the time. The other two categories occur less than half of the​ time, with category Upper B being the least likely to occur.

s part of the marketing group at a film​ studio, you are asked to find out the age distribution of the audience of the​ studio's latest family friendly film. With the help of 10 of your​ colleagues, you conduct exit interviews by randomly selecting people to question at 20 different movie theaters. From 454 ​responses, you find out that 39 are younger than​ 6, 81 are 6 to 9 years​ old, 148 are 10 to​ 14, 20 are 15 to​ 21, and 166 are older than 21. Complete parts a and b below.

a.) Age Range/ Frequency Under 6: 39 6 to 9: 81 10 to 14: 148 15 to 21: 20 Over 21: 166 ​b) Make a relative frequency table Age Range/Relative Frequency Under 6: 8.59​% 6 to 9: 17.84​% 10 to 14: 32.59​% 15 to 21: 4.40​% Over 21: 36.56​%