The following are the duration in minutes of a samle of long distance phone call

Question

The following are the duration in minutes of a samle of long distance phone calls made within the continental United States reported by one long distance carrier.

Time in Minutes                   Relative Frequency

0 but less than 5                 0.37

5 but less than 10               0.24

10 but less than 15             0.07

15 but less than 20             0.08

20 but less than 25            0.15

25 but less than 30            0.08

30 or more                           0.01

1. If 100 calls were randomly sampled, how many calls lasted under 50 minutes?

2.If 1000 calls were randomly sampled, how many calls lasted 15 minutes or longer?

3. Form the cumulative percentage distribution.

Explanation / Answer

1. If 100 calls were randomly sampled, how many calls lasted under 50 minutes?

The percetage of the calls lasted under 50 minutes is

0.37+0.24+0.07+0.08+0.15+0.08+0.01 = 1

So 100*1=100 calls

------------------------------------------------------------------------------------------------------------------------

2.If 1000 calls were randomly sampled, how many calls lasted 15 minutes or longer?

The percetage of calls lasted 15 minutes or longer is

0.08+0.15+0.08+0.01 =0.32

So 1000*0.32 =320 calls

------------------------------------------------------------------------------------------------------------------------

3. Form the cumulative percentage distribution.

Time in mimutes Relative Frequency cumulative percentage distribution 0 but less than 5 0.37 0.37 5 but less than 10 0.24 0.61 10 but less than 15 0.07 0.68 15 but less than 20 0.08 0.76 20 but less than 25 0.15 0.91 25 but less than 30 0.08 0.99 30 or more 0.01 1

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.