6-7 Dot Plots Objective Create and interpret dot plots.

D OT P LOT A data display in which each data item is shown as a dot above a number line (like a histogram, but with dots) Cluster : group of data points Gap : where there are no data items. Cluster Gap

D OT P LOT (N UMBER LINE P LOT ) A statistical graphic where dots represent data values and are plotted above a number line. Example: Suppose you count the number of students in each Algebra 1 classroom in your school. In your data there are only a few classrooms, you can use a line plot to organize.

S TEPS TO C REATE A D OT P LOT 1.Order numbers from least to greatest. 2.Draw a number line. 3.Label the number line with the minimum and the maximum then all the numbers in between. 4.Put a dot above each number on the number line for each data entry in your set. 5.Don’t forget a title and labels!

In an airline training program, the students are given a test in which they are given a set of tasks and the time it takes them to complete the tasks is measured. The following is a list of the time (in seconds) for a group of new trainees. 61, 61, 64, 67, 70, 71, 71, 71, 72, 73, 74, 74, 75, 77, 79, 80, 81, 81, 83 A. Display the data in a dot plot. = 1 person Example 1: Airline Training Program Test New Trainees Time in Seconds

In an airline training program, the students are given a test in which they are given a set of tasks and the time it takes them to complete the tasks is measured. The following is a list of the time (in seconds) for a group of new trainees. 61, 61, 64, 67, 70, 71, 71, 71, 72, 73, 74, 74, 75, 77, 79, 80, 81, 81, 83 A. Display the data in a dot plot. = 1 person Example 1: Airline Training Program Test New Trainees Time in Seconds

B. W HAT IS THE AVERAGE TIME ? Airline Training Program Test New Trainees = 1 person Time in Seconds 61(__) (__) (__) (__) + 83 _____/19 = ?? About ___ seconds Example 1: Continued

B. W HAT IS THE AVERAGE TIME ? Airline Training Program Test New Trainees = 1 person Time in Seconds 61(2) (3) (2) (2) /19 = About 73 seconds Example 1: Continued

C. W HAT IS THE MEDIAN TIME ? Airline Training Program Test New Trainees = 1 person Time in Seconds _____ seconds The _____ th dot is the median D. W HAT DOES THE MEDIAN REPRESENT ? The center of the data set. Example 1: Continued

C. W HAT IS THE MEDIAN TIME ? Airline Training Program Test New Trainees = 1 person Time in Seconds seconds The 10 th dot is the median D. W HAT DOES THE MEDIAN REPRESENT ? The center of the data set. Example 1: Continued

E. W HAT IS THE M ODE ? Airline Training Program Test New Trainees = 1 person Time in Seconds _____ seconds

E. W HAT IS THE M ODE ? Airline Training Program Test New Trainees = 1 person Time in Seconds seconds

F. W HAT IS THE R ANGE ? Airline Training Program Test New Trainees = 1 person Time in Seconds G. W HAT DOES THE RANGE REPRESENT ? The variation in the data set.

F. W HAT IS THE R ANGE ? Airline Training Program Test New Trainees = 1 person Time in Seconds seconds83 – 61 = G. W HAT DOES THE RANGE REPRESENT ? The variation in the data set.

S YMMETRIC Two halves look like mirror images of each other.

T AIL Some distributions have a tail stretching left or right. These are seen in distributions that are skewed to the left (Negative) or skewed to the right (Positive) Skewed to the right Skewed to the left

Classwork/Homework 6-7 Worksheet