Question

20 electric bulbs randomly selected from a production lot were burnt until they fused, giving a mean burning life 40 of 400 hours and S.D. of 40 hours. Find whether at 5% level of significance, the production lot could claim a mean burning life of 500 hours.

Answer 1

Answer:

(getting a defective bulb) =p=10/100=1/10=0.1

Q(getting a working bulb)q=1−p=9/10=0.9

Suppose X has a bionomial distribution, the probability of x success in n-Bernoulli trials,

Here in this case getting a defective bulb is success,

P(X=x)=nCx∗px∗qn–x where in x=0,1,2,...,n some finite number of required successes out of some finite number of trials(n)

Therefore,