Question

In a poll conducted by the General Social Survey, 81% of respondents said that their jobs were sometimes or always stressful. Two hundred workers are chosen at random.

a. Approximate the probability that 160 or fewer find their jobs stressful.

b. Approximate the probability that more than 150 find their jobs stressful.

Answer 1

Solution:

The mean and standard deviation of the given data is:

a. We have to find:

Now using the standard normal table, we have:

Therefore, the probability that 160 or fewer find their jobs stressful is 0.3592

b. We have to find:

Now using the standard normal table, we have:

Therefore, the probability that more than 150 find their jobs stressful is 0.9847