Question

The life span of 100 W light bulbs manufactured by a company are tested. It is...

The life span of 100 W light bulbs manufactured by a company are tested. It is found that (2%) of the light bulbs are rejected. A random sample of 15 bulbs is taken from stock and tested. The random variable X is the number of bulbs that is rejected.

If life span of light bulbs is adjusted so that the mean now is ?. Find the value of ?:

i. Given that ?(? = 0) = 0.25.

ii. Given that the variance of ? is 2.4.

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