38.Interval data may be treated as ordinal or nominal.
39.Nominal data may be treated as ordinal or interval
40.A histogram is said to be symmetric if, when we draw a vertical line down thecenter of the histogram, the two sides are identical in shape and size.
41.A skewed histogram is one with a long tail extending either to the right orleft. The former is called negatively skewed, and the later is called positivelyskewed.
42.A bimodal histogram is one with two peaks equal in height.

Graphical
Descriptive Techniques
12
43.Bar and pie charts are graphical techniques for nominal data. The formerfocus the attention on the frequencyof the occurrences of the categories,and the later emphasize the proportion of occurrences of each category.
44.The graphical technique used to describe the relationship between twointerval variables is the scatter diagram.
45.If we draw a straight line through the points in a scatter diagram and most ofthe points fall close to the line, we say that there is a positive linearrelationship between the two variables.
46.Time series data are often graphically depicted on a line chart, which is a plotof the variable of interest over time.
47.Professor Hogg graduated from the University of Iowa with a code value = 2while professor Maas graduated from Michigan State University with a codevalue = 1. The scale of measurement likely represented by this information isratio.
48.ATP singles rankings for tennis players is an example of an interval scale.
49.Quantitative variables usually represent membership in groups or categories.
50.An automobile insurance agent believes that company “A” is more reliablethan company “B”. The scale of measurement that this informationrepresents is the ordinal scale.
51.When a distribution has more values to the left and tails to the right, it isskewed negatively.
52.When a distribution has more values to the right and tails to the left, we sayit is skewed positively.

13 Chapter Two
TEST QUESTIONS
53.Identify the type of data for which each of the following graphs isappropriate.a.Histogramb.Pie chartc.Bar chart
ANSWERS:
a.Intervalb.Nominal c.Nominal54.Before leaving a particular restaurant, customers are asked to respond to thequestions listed below. For each question, determine whether the possibleresponses are interval, nominal, or ordinal.a.What is the approximate distance of the restaurant from your residence?b.Have you eaten at the restaurant previously?c.If your answer to part (b) was yes, on how many occasions? d.Which of the following attributes of the restaurant do you find mostattractive: service, prices, quality of the food, or varied menu?e.Would your overall rating of the restaurant be excellent, good, fair, orpoor?

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- Spring '08
- ROCHON
- Frequency distribution, Histogram