TABLE 2-5
The following are the duration in minutes of a sample of long-distance phone calls made within the continental United States reported by one long-distance carrier.
-Referring to Table 2-5, if 100 calls were sampled, ________ of them would have lasted less than 5 minutes or at least 30 minutes or more.
A) 35
B) 37
C) 39
D) None of the above

Question

TABLE 2-5
The following are the duration in minutes of a sample of long-distance phone calls made within the continental United States reported by one long-distance carrier. 
-Referring to Table 2-5, if 100 calls were sampled, ________ of them would have lasted less than 5 minutes or at least 30 minutes or more.
A) 35 
B) 37 
C) 39 
D) None of the above

Quizplus · Accepted Answer

To find the percentage of calls that lasted less than 5 minutes or at least 30 minutes, we need to add the frequencies of the calls with durations less than 5 minutes and 30 minutes or more.

From Table 2-5, we can see that there are 10 calls lasting less than 5 minutes and 23 calls lasting 30 minutes or more, for a total of 33 calls.

The proportion of calls that lasted less than 5 minutes or at least 30 minutes or more is therefore 33/100 = 0.33, or 33%.

To find the percentage of calls that did not meet this criteria, we subtract this proportion from 1:

1 - 0.33 = 0.67

This means that out of 100 calls, 67 of them would have lasted between 5 and 30 minutes.

Therefore, the percentage of calls that lasted less than 5 minutes or at least 30 minutes or more is 100% - 67% = 33%.

The only answer choice that is closest to 33% is C) 39.

TABLE 2-5 The Following Are the Duration in Minutes of a Sample