The following table gives the cumulative frequency distribution of the commuting time (in minutes) from home to work for a sample of 400 persons selected from a city.

Time (minutes)

f

0 to less than 10

66

0 to less than 20

156

0 to less than 30

217

0 to less than 40

291

0 to less than 50

344

0 to less than 60

400

The sample size is:

The percentage of persons who commute for less than 30 minutes, rounded to two decimal places, is:

%

The cumulative relative frequency of the fourth class, rounded to four decimal places, is:

The percentage of persons who commute for 40 or more minutes, rounded to two decimal places, is:

%

The percentage of persons who commute for less than 50 minutes, rounded to two decimal places, is:

%

The number of persons who commute for 20 or more minutes is: