Chapter 13.4, Problem 9PPS

(a)

To determine

To find: the percent of the hurricanes had top wind speeds less than 65 miles per hour.

Answer to Problem 9PPS

50%

Explanation of Solution

Given information:

The top wind speeds for hurricanes in a recent year are shown below,

  

Calculation:

The given box and whisker plot shows top wind speed of hurricanes in recent year. It is required to know what percent of the hurricanes had top wind speeds less than 65 per hour.

Locate 65 in the number scale of the given box and whisker plot. Note that box and whisker plot separates the data into four parts excluding outlier. The distance between minimum and lower quartile comprise 25%, lower quartile to median comprises 25%, median to upper quartile comprises 25% and upper quartile to maximum comprises 25%. Thus, around 50% of the hurricanes had top wind speeds less than 65 miles per hour.

(b)

To determine

To find: the length of the box tells about the data.

Explanation of Solution

The median divides the data in the box into two unequal parts. The data between median andupperr quartile are more clustered than median and lower quartile. The whiskers are of different length, that is data above the upper quartile has higher range compared to data below the lower quartile .