Question

5,8,10,20,25,30,35,40,45
what is the lower quartile of data set above.
A.5
B.5
C.9
D.10

Answer 1

5,8,10,20,25,30,35,40,45

Quartile 1 is your lower quartile
Q2 is your median...middle number
Q3 is your upper quartile

Q2 would be 25
Q1 (upper quartile) is the median of the numbers before Q2

so Q1 is : (8 + 10) / 2 = 18/2 = 9 (your lower quartile).