Exhibit 2-10.Automobiles traveling on a road with a posted speed limit of 65 miles per hour are checked for speed by a state police radar system.The following table is a frequency distribution of speeds. Refer to Exhibit 2-10.What proportion of the cars traveled at least 55 but less than 65 miles per hour?
A)0.33
B)0.48
C)0.56
D)0.80

Question

Exhibit 2-10.Automobiles traveling on a road with a posted speed limit of 65 miles per hour are checked for speed by a state police radar system.The following table is a frequency distribution of speeds.  Refer to Exhibit 2-10.What proportion of the cars traveled at least 55 but less than 65 miles per hour?
A)0.33 
B)0.48 
C)0.56 
D)0.80

Quizplus · Accepted Answer

To find the proportion of cars that traveled at least 55 but less than 65 miles per hour, we need to sum up the frequencies for speeds between 55 and 65 and divide it by the total number of cars.

The frequency for speeds between 55 and 65 is 16 + 19 + 12 = 47

The total number of cars is the sum of all frequencies, which is 100.

So, the proportion is 47/100 = 0.47, which is closest to choice B (0.48).