Hen 430 randomly selected light bulbs were tested in a laboratory, 224 lasted more than 500 hours. find a point estimate of the last more than 500 hours proportion of all light bulbs thata 0.479b 0.343c 0.519d 0.521

By the definition, An observed value of \bar{x} to estimate the mean of population is a point estimate and the statistic \bar{x} is a poiont estimator.

It is given that, "Hen 430 randomly selected light bulbs were tested in a laboratory"

That is, the Random sample size n= 430

The statement given that, "224 lasted more than 500 hours"

So x=224

Now find a point estimate of the last more than 500 hours proportion of all light bulbs:

Thus

This implies that

Thus the answer is D: 0.521.

a. is correct