Question

determine the modal lifetime​

Answer 1

Answer:

65 hrs 37 mins 30secs

Step-by-step explanation:

formula used

Mode = l + (f₁-f₀/2f₁-f₀-f₂) ×h

where,

 l = lower limit of the modal class

 h = size of the class intervals

 f₁ = frequency of the modal class

 f₀ = frequency of the class preceding the modal class

 f₂ = frequency of the class succeed in the modal class.

As per the frequency table

frequency(max) is 61,

class corresponding to this frequency is 60 – 80. hence it is the modal class.

so we have,

l = 60

h = 80 – 60 = 20

f1 = 61

f0 = 52

f2 = 38

Mode  = l + [ ( f₁-f₀) /  (2f₁-f₀-f₂)] ×h

where,

          = 60 + [(61 - 52)/(2 × 61 - 52 – 38) ]×20

          = 60 +[(9 × 20)/(122 - 90)]

          = 60 + [180/32]

          = 60 + 5.625

          = 65.625 hrs

          = 65 hrs 37 mins 30secs