Two data sets, R and S, each consist of 15 integers and are summarized in the histograms shown. For each histogram, the first interval represents the frequency of integers greater than or equal to 10 but less than 20, the second interval represents the frequency of integers greater than or equal to 20 but less than 30, and so on.
Data Set R:
Interval [10,20): Frequency 4
Interval [20,30): Frequency 6
Interval [30,40): Frequency 5
Data Set S:
Interval [15,25): Frequency 4
Interval [25,35): Frequency 6
Interval [35,45): Frequency 5
What is the greatest possible difference between the mean of data set R and the mean of data set S?
12
14
15
20
