The following data gives the information on the observed lifetime (in hours) of 225 electrical components:
Life time (in hours)0−2020−4040−6060−8080−100100−120Number of components103552613829
Determine the modal lifetimes of the components, given that the modal class is 60-80.
65.62
Given that the modal class is 60-80.
Here,
L=60,D1=61−52=9
D2=61−38=23,h=20
Mode=L+D1D1+D2×h=60+99+23×20=65.62 hours