Mathematics for IGCSE & O level - Statistical Diagrams (Section 3 - No. 2)
How do you calculate the 90th percentile using a cumulative frequency diagram?
Find the value on the x-axis corresponding to the 10th percentile on the y-axis.
Find the value on the x-axis corresponding to the 90th percentile on the y-axis.
Calculate the difference between the 50th and 90th percentile on the y-axis.
The 90th percentile cannot be found using a cumulative frequency diagram.
Paliwanag
The 90th percentile is the value on the x-axis that corresponds to the cumulative frequency representing 90% of the data.