Question 1 - Page 107 - Median vs. Mean - Chapter 5 Class 7 - Connecting the Dots... (Ganita Prakash II)

Transcript

Question 1 - Page 107 Find the mean and median in Poovizhi’s data without the outlier value 118. What change do you notice?Poovizhi’s family’s height was 170 cm, 173 cm, 165 cm, 118 cm, 175 cm After removing the outlier 118 cm New Data: Heights are now 165 cm, 170 cm, 173 cm, 175 cm New Mean: Mean = (𝑆𝑢𝑚 𝑜𝑓 𝑑𝑎𝑡𝑎)/(𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑑𝑎𝑡𝑎) =(165 + 170 + 173 + 175)/4 =683/4 =𝟏𝟕𝟎.𝟕𝟓 cm New Median: Writing Heights in ascending order 165 cm, 170 cm, 173 cm, 175 cm Number of observations = 4 Since number of observations is even, We use the average of the two middle numbers Our middle numbers are 170 cm & 173 cm Thus, Median = (170 + 173)/2 = 343/2 = 171.5 cm What change do we notice? The Mean jumped up a lot (from 160.2 to 170.75 ). It is very sensitive to the outlier. The Median stayed almost the same (from 170 to 171.5 ). It is very stable.