The middle 50% (middle half) of the data has a range of 5.5 inches.

The interval 59вЂ“65 has more than 25% of the data so it has more data in it than the interval 66 through 70 which has 25% of the data.

Range = maximum value вЂ“ the minimum value = 77 вЂ“ 59 = 18.So, the second quarter has the smallest spread and the fourth quarter has the largest spread. The spreads of the four quarters are 64.5 вЂ“ 59 = 5.5 (first quarter), 66 вЂ“ 64.5 = 1.5 (second quarter), 70 вЂ“ 66 = 4 (third quarter), and 77 вЂ“ 70 = 7 (fourth quarter).Each quarter has approximately 25% of the data.The following data are the heights of 40 students in a statistics class.ДҐ9 60 61 62 62 63 63 64 64 64 65 65 65 65 65 65 65 65 65 66 66 67 67 68 68 69 70 70 70 70 70 71 71 72 72 73 74 74 75 77Д¬onstruct a box plot with the following properties the calculator instructions for the minimum and maximum values as well as the quartiles follow the example. The box plot gives a good, quick picture of the data. The median or second quartile can be between the first and third quartiles, or it can be one, or the other, or both.

The вЂњwhiskersвЂќ extend from the ends of the box to the smallest and largest data values. Approximately the middle 50 percent of the data fall inside the box. The first quartile marks one end of the box and the third quartile marks the other end of the box. The smallest and largest data values label the endpoints of the axis. To construct a box plot, use a horizontal or vertical number line and a rectangular box.

We use these values to compare how close other data values are to them. A box plot is constructed from five values: the minimum value, the first quartile, the median, the third quartile, and the maximum value. They also show how far the extreme values are from most of the data. Recognize, describe, and calculate the measures of location of data: quartiles and percentiles.Д«ox plots (also called box-and-whisker plots or box-whisker plots) give a good graphical image of the concentration of the data.Display data graphically and interpret graphs: stemplots, histograms, and box plots.

Box and whisker plot lower quartile