A researcher conducts a mileage economy test involving 82 cars. The frequency distribution describing average miles per gallon (mpg) appears in the following table.
|
Average mpg
|
Frequency
|
|
15 up to 20
|
10
|
|
20 up to 25
|
16
|
|
25 up to 30
|
4
|
|
30 up to 35
|
12
|
|
35 up to 40
|
29
|
|
40 up to 45
|
11
|
a-1. Construct the corresponding relative frequency, cumulative frequency, and cumulative relative frequency distributions.
b-1. How many of the cars got less than 25 mpg?
b-2. What percent of the cars got at least 30 but less than 35 mpg? (Round your answer to 2 decimal place.)
b-3. What percent of the cars got less than 20 mpg? (Round your answer to 2 decimal place.)
b-4. What percent got 20 mpg or more? (Round your answer to 2 decimal place.)