Astudent was investigating how many students in their class share a car ride to school.
the table shows the results.
if 26 students travel by car, and some student travel together, answer the following.
(a) what is the missing frequency?
(b) what is the mean number of students in each car?
number of students in one car number of cars
1 n
2 7
3 3

If 26 students were riding, then the missing frequency for the number of cars for each student. Because:

2x7 = 14
+
3x3 =9 
=
23 students. Therefore there were 3 cars with only 1 student riding in each car. 

The mean number of students in each car is 2. Because:

mean for 3 cars = 1
mean for 7 cars = 2
mean for 3 cars = 3

Add it all up and divide by 3 means yields 2. 

The answer for this is 9/1253decimal form 0.007