statistics and probability 6 cum freq curve

Mathematics Dr. Vishwas Parlikar

Name: _______________________________________ Homework 40

Date: 15.12.2011 Due: 16.12.2011

IGCSE: STATISTICS AND PROBABILITY

Objective: Plot ogive curve to FIND median and quartiles of a data set.

1 The cumulative frequency curve below shows the heights of 120 basketball players in centimetres.

(a) Use the curve to estimate:

(i) the median height (ii) the inter-quartile range.

(b) Use the cumulative frequency curve to complete the frequency table below.

Height (x) 160 ≤ x < 170 170 ≤ x < 180 180 ≤ x < 190 190 ≤ x < 200

Number of players 14

Calculate an estimate of the mean height.

Mathematics Dr. Vishwas Parlikar

2 Kristina asked 200 people, how much water they drink in a day. The results were:

(a) Draw cumulative frequency graph for the data.

(b) Use cumulative frequency graph to find: (i) median amount (ii) 40th percentile (iii) number of people who drink at least 2.6 litres of water (iv) percentage of people who drink at least 1.8 litres of water