Exam 4: Graphical Descriptive Techniques Numerical Data

A stem-and-leaf display describes two-digit integers between 20 and 70. For one of the classes displayed, the row appears as 4 | 2 5 6. The numerical values being described are 42, 45 and 46.

Construct an ogive for the test grades for a university business statistics class, and estimate the proportion of grades that are between 80 and 90. 63 74 42 65 51 54 36 56 68 57 62 64 76 67 79 61 81 77 59 38 84 68 71 94 71 86 69 75 91 55 48 82 83 54 79 62 68 58 41 47

Which of the following statements is true?

Which of the following is the sum of the relative frequencies for all classes?

A list of share prices of one Australian company, at the end of a trading day for the period of 30 trading days, would be an example of time-series data.

Construct a frequency distribution and relative frequency distribution for the test grades for a university business statistics class, data given in the following table. Use seven class intervals. 63 74 42 65 51 54 36 56 68 57 62 64 76 67 79 61 81 77 59 38 84 68 71 94 71 86 69 75 91 55 48 82 83 54 79 62 68 58 41 47

Which of the following best describes the modal class? A. The class with the largest number of observati ons. B. The class with the smallest number of observations. C. The class with the largest observati on in the data set. D. The dass with the smallest obsertation in the data set.

The number of faulty items returned to a manufacturer of electric goods in the last 15 years is as follows: Year No. of faulty items 1996 27 1997 35 1998 34 1999 39 2000 43 2001 42 2002 40 2003 41 2004 45 2005 47 2006 46 2007 50 2008 49 2009 52 2010 52 a. Construct a relative frequency bar chart for these data. b. Construct a line chart.

With a line graph, the horizontal axis is stretched out to get a deceptive steeper slope.

Which of the following statements is false?

The graphical format used to display the relationship between two numerical (quantitative) variables is the scatter diagram.

The lowest value in a set of data is 140, and the largest value is 270. If the resulting frequency distribution is to have ten classes of equal width, the common class width will be 27.

Individual observations within each class may be found in a frequency distribution.

Which of the following may be determined from the height of the bar in a relative frequency histogram?

A list of share prices of 20 Australian companies at the end of a trading day would be an example of time-series data.

Graphical deception is acceptable when the graph displays what the statistician would like the reader to believe, as opposed to the truth about the data.

A relative frequency distribution describes the number of data values that fall within each class, and may be presented in histogram form.

The strength of a linear relationship between two numerical variables may be illustrated by a line graph, where the closer the points form a line, the stronger the linear relationship between the two variables.

The table below shows the number of licensed hotels with at least 15 rooms in New South Wales from March 1998 to December 2009. a. Plot the time series. b. When did the number of licensed hotels with at least 15 rooms in New South Wales grow fastest?

Consider the following cumulative frequency distribution. Class limits Cumulative frequency Up to 10 12 Up to 20 29 Up to 30 57 Up to 40 71 Up to 50 95 Find the frequency for each of the following classes. a. 0 up to 10. b. 10 up to 20. c. 20 up to 30. d. 30 up to 40. e. 40 up to 50.