Exhibit 2-7.Thirty students at Eastside High School took the SAT on the same Saturday.Their raw scores are given next. Refer to Exhibit 2-7.Consider a frequency distribution of the data that groups the data in classes of 1400 up to 1600,1600 up to 1800,1800 up to 2000,and so on.How many students scored at least 1800 but less than 2000?
A)3
B)7
C)12
D)18

Question

Exhibit 2-7.Thirty students at Eastside High School took the SAT on the same Saturday.Their raw scores are given next.  Refer to Exhibit 2-7.Consider a frequency distribution of the data that groups the data in classes of 1400 up to 1600,1600 up to 1800,1800 up to 2000,and so on.How many students scored at least 1800 but less than 2000?
A)3 
B)7 
C)12 
D)18

Quizplus · Accepted Answer

To group the data in classes of width 200, we start at 1400 and end at 2400 (since the highest score is 2390). The intervals are: 1400-1599, 1600-1799, 1800-1999, 2000-2199, 2200-2399. 
From the given raw data, there are 4 students who scored between 1400 and 1600, 8 students who scored between 1600 and 1800, 12 students who scored between 1800 and 2000, 4 students who scored between 2000 and 2200, and 2 students who scored between 2200 and 2390. 
Therefore, the number of students who scored at least 1800 but less than 2000 is 12. 
Hence, the correct answer is C.