Question

The speed of 14 randomly selected vehicles passing through a construction zone is given: 20 24 27 28 29 30 32 33 34 36 38 39 40 40

(a) Use Excel to find the five-number summary for the observed speeds

• On your worksheet, add a new column anywhere with the data.

• Click the Insert Function fx button in the Formula Bar

• Select the category Statistical in the Insert Function dialog box 3

• In the Select a Function box, click QUARTILE.INC and click OK

• In the Function Argument dialog box, click Array and enter the range of data values, such as A1:A14 for data stored in column A

• In the Quart box, enter 0 to find the minimum, 1 to find the 1st quartile, and similarly enter 2, 3, 4 for the other values.

Submit your printout with a title and label each of the five numbers.

(b) Use Excel to construct a boxplot for the observed speeds.

• Select the data in the worksheet and click Insert.

• Click Chart and then Box and Whisker

Submit your printout with a title and label the axis of your boxplot.

(c) Use the boxplot to determine the shape of the distribution

Answer 1

Put the data in excel.

Step 1 : In Fx select quartile.

Step 2 : use the formula as shown

Boxplot

Go to insert, select chart and then all chart.

The box and whisker plot will be provided as follow

The data is left skew as you see that most of the data point are on the higher side and few on the lower side.