The following are the durations in minutes of a sample of long-distance phone calls 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	0.22
10 but less than 15	0.15
15 but less than 20	0.10
20 but less than 25	0.07
25 but less than 30} 0.07
30 or more	0.02

i) What is the width of each class?

a. 1 minute

b. 2%

c. 5 minutes

d. 100%

ii) What is the cumulative relative frequency for the percentage of calls that lasted under 10 minutes?

a. 0.10

b. 0.76

c. 0.59

d. 0.84