Question

. The following data gives the information on the observed lifetimes (in hours) of 287 electrical components.
Find the modal life of the components,
lifetimes (in hours)
0 - 20
20
40
40
60
60
80
80
100
100 - 120
Frequency
26
31
35
42.
82.
71​

Answer 1

Answer:

the class 80-100 has the highest frequency.So it is a modal class.

then

lower boundary=80

frequency of modal class=82

preceding frequency of modal class=42

succeeding frequency of modal class=71

class size=20

mode=l+(f1-f0/2f1-f0-f2)h

=80+(82-42/2(82)-42-71)20

=80+(40/164-113)20

=80+(40/51)20

=80+800/51

=80+15.68

=95.68

the modal life of the components is 95.67