Math 50 – Section #3.3 Name ____________________

Dotplots, Stemplots, and Time-Series Plots

Professor Jason Wang

1. The following data set are students’ scores (in points) on an exam in an

intermediate algebra class:

73 85 63 97 71 64 95 83 34 84 38 53

88 53 85 80 95 84 70 35 77 65 91 58

72 61 46 86 81 82 83 73

Use this data set to complete each of the following exercises.

(a) Construct a dotplot for this data set.

(b) Construct a stem-and-leaf plot for this data set.

- A time-series plot of the average spending (in dollars) of a college student on

course materials is shown below.

Use the above time-series plot to answer each of the following questions.

Use appropriate units and write your answer in complete sentences.

(a) Estimate the average spending on course materials in 2011.

(b) Estimate the year when the average annual spending on course materials

was $640.

(c) Estimate the change in average annual spending on course materials from

2012 to 2013

(d) When looking at the average annual spending on course materials from

2007 to 2013, has it generally increased, stayed approximately constant,

generally decreased, or none of the above? Briefly explain your answer.