Answer:
The probability of a bulb lasting for at most 552 hours.
P(x>552) = 0.0515
Step-by-step explanation:
Step(i):-
Given mean of the life time of a bulb = 510 hours
Standard deviation of the lifetime of a bulb = 25 hours
Let 'X' be the random variable in normal distribution
Let 'x' = 552
[tex]Z = \frac{x-mean}{S.D} = \frac{552-510}{25} =1.628[/tex]
Step(ii):-
The probability of a bulb lasting for at most 552 hours.
P(x>552) = P(Z>1.63)
= 1- P( Z< 1.63)
= 1 - ( 0.5 + A(1.63)
= 1- 0.5 - A(1.63)
= 0.5 -A(1.63)
= 0.5 -0.4485
= 0.0515
Conclusion:-
The probability of a bulb lasting for at most 552 hours.
P(x>552) = 0.0515
