A sociologist recently conducted a survey of citizens over 60 years of age who have net worths too high to qualify for Medicaid but have no private health insurance. The ages of the 25 uninsured senior citizens were as follows: $$\begin{array} { l l l l l l l l l l l l l }
68 & 73 & 66 & 76 & 86 & 74 & 61 & 89 & 65 & 90 & 69 & 92 & 76 \
62 & 81 & 63 & 68 & 81 & 70 & 73 & 60 & 87 & 75 & 64 & 82 &
\end{array}$$ Find the upper quartile of the data.
A) 81.5
B) 65.5
C) 73
D) 92

Question

A sociologist recently conducted a survey of citizens over 60 years of age who have net worths too high to qualify for Medicaid but have no private health insurance. The ages of the 25 uninsured senior citizens were as follows: $$\begin{array} { l l l l l l l l l l l l l } 
68 & 73 & 66 & 76 & 86 & 74 & 61 & 89 & 65 & 90 & 69 & 92 & 76 \
62 & 81 & 63 & 68 & 81 & 70 & 73 & 60 & 87 & 75 & 64 & 82 &
\end{array}$$ Find the upper quartile of the data.
A) 81.5
B) 65.5
C) 73
D) 92

Quizplus · Accepted Answer

The upper quartile (Q3) is the median of the upper half of the data. First, sort the data: 60, 61, 62, 63, 64, 65, 66, 68, 68, 69, 70, 73, 73, 74, 75, 76, 76, 81, 81, 82, 86, 87, 89, 90, 92. The upper half is 73, 74, 75, 76, 76, 81, 81, 82, 86, 87, 89, 90, 92. The median of this set is 81.5.

A Sociologist Recently Conducted a Survey of Citizens Over 60