(i) Advantage: A box-and-whisker plot provides a visual summary of data distribution, showing the median, quartiles, and potential outliers, which helps in understanding the spread and shape of the data.

Disadvantage: It does not provide detailed information about individual data points or the exact distribution of data within the quartiles.

(iii)(a) To draw the box-and-whisker plot:

• Identify the minimum value: 190
• Identify the maximum value: 375
• Calculate the median: 280
• Calculate the lower quartile (LQ): 256 or 256.5
• Calculate the upper quartile (UQ): 329

Draw the box from LQ to UQ with a line at the median. Extend whiskers from the minimum to LQ and from UQ to the maximum.

(iii)(b) The interquartile range (IQR) is calculated as:

\(IQR = UQ - LQ = 329 - 256 = 73\) or \(329 - 256.5 = 72.5\)