Find the quartiles for these data values:
5,7,7,8,10,11,12,15,17
A. Q1=7 , Q2=11, Q3=15
B. Q1=7, Q2=10, Q3=13.5
C. Q1=6, Q2=9, Q3=12
D. Q1=7.5, Q2=10.5, Q3=13.5
To find the quartiles for these data values, they need to be arranged in ascending order:
5, 7, 7, 8, 10, 11, 12, 15, 17
Step 1: Find the median (Q2).
Since there are 9 data points, the median would be the middle value, which is 10.
Step 2: Find the lower quartile (Q1).
Since there are an odd number of data points below the median, Q1 would be the middle value of the lower half. The lower half is {5, 7, 7, 8}. The middle value of this set is 7.
Step 3: Find the upper quartile (Q3).
Since there are an odd number of data points above the median, Q3 would be the middle value of the upper half. The upper half is {11, 12, 15, 17}. The middle value of this set is 13.
Hence, the correct answer is:
B. Q1=7, Q2=10, Q3=13.5