Here , frequency of class interval 60−80 is maximum.So, it is the modal classNow, l= Lower limit of modal class =60f1​= Frequency of modal class =61f0​= Frequency of class preceding the modal class =52f2​ = Frequency of class succeeding the modal class =38h= Class interval width = 20So, Mode =l+(2f1​−f0​−f2​f1​−f0​​)×h=60+(2(61)−52−3861−52​)×20=60+(122−909​)×20=60+(329​)×20=60+5.625Mode =65.625Therefore, modal lifetime of electrical components is 65.625 hours