The National Environmental Agency records the monthly rainfall (in mm) in Singapore.
The cumulative frequency diagram represents the monthly rainfall from 2021 to 2025.
Use the diagram to estimate
the median monthly rainfall,[1]
the interquartile range of the monthly rainfall.[2]
A monthly rainfall of 50 mm and below is classified as extremely dry in Singapore.
Based on the data provided for the period 2021 to 2025, calculate the probability that a randomly selected month is not classified as extremely dry.[2]
The rainfall measurements, in mm, for the first five months of 2026 are recorded as
9.4 mm, 202.2 mm, 38.2 mm, 179.8 mm, and 185.2 mm.
By considering the inclusion of these five new data points into the original dataset, explain how the median will change. Justify your reasons.[2]