Solution

(i) Construct the stem-and-leaf diagram:

Key: \(1 \mid 4\) represents \$140.

(ii) Find the median and interquartile range:

Ordered data: 10, 40, 60, 80, 100, 130, 140, 140, 140, 150, 150, 150, 160, 160, 160, 160, 170, 180, 180, 200, 210, 250, 270, 280, 310, 450, 570

\(\text{Median} = 160\) (14th value)

\(\text{LQ} = 140\) (7th value), \(\text{UQ} = 210\) (21st value)

\(\text{IQR} = \text{UQ} - \text{LQ} = 210 - 140 = 70\)

(iii) Identify outliers:

\(1.5 \times \text{IQR} = 1.5 \times 70 = 105\)

\(\text{Lower limit} = 140 - 105 = 35\)

\(\text{Upper limit} = 210 + 105 = 315\)

Outliers: 10, 450, 570