Question

Suppose that a poll taken 10 years ago found that 69% of parents hug their children. Suppose a recent poll of 350 adults with children finds that 217 indicated that they hug their children. The expected amount of parents surveyed that would hug their children is 242.

B.) Do the results of the survey suggest that parents' attitude toward hugs may have changed since the original poll? Why?

-Yes, 217 is outside the "usual" observation interval.

- Yes, 217 is less than the expected amount of adults that hug their children

- No, 217 is inside the "usual" observation interval.

- No, 217 is within one standard deviation of the expected amount of adults that hug their children.

Answer 1

The following information about the Binomial distribution is provided:

The population proportion of success is p = 0.69, and the sample size is n= 350

As per empirical rule, usual interval is as follows:

μ - 2*σ < x <  μ + 2*σ

241.5 - 2*8.6525 < x <  241.5 + 2*8.6525

224.195 < x < 258.805

Since 217 is outside the "usual" observation interval, we can say that parents' attitude toward hugs may have changed since the original poll.

Correct Answer:

Yes, 217 is outside the "usual" observation interval