Exam 9: Introduction to Estimation

The sampling distribution of is approximately normal if the sample size is more than 30.

A specific confidence interval obtained from data will always correctly estimate the population parameter.

An interval estimate is a range of values within which the actual value of the population parameter, such as $\mu$ , may fall.

Which of the following would be an appropriate alternative hypothesis?

As the bound on the error of estimation decreases, the sample size ____________________.

Because n is an integer and we want the bound on the error of estimation to be no more than a given amount, any non-integer value found for n must always be rounded ____________________.

The width of a confidence interval estimate for a proportion will be:

The version of the sample variance where you divide by ____________________ gives you an unbiased estimator of the population variance.

If the bound on the error of estimation decreases, the sample size ____________________.

In determining the sample size needed to estimate the population proportion p, we let the sample proportion = 1 if we have no knowledge of even the approximate values of .

The use of the standard normal distribution for constructing confidence interval estimate for the population proportion p requires:

Draw a sampling distribution of an unbiased estimator for $\mu$ .

____________________ estimators reflect the effects of larger sample sizes, but ____________________ estimators do not.

The bound on the error of estimation is the ____________________ amount of sampling error that we are willing to tolerate.

Socialist Party Voters: A pollster in Italy wants to challenge a claim that 5% of the registered voters in his country are Socialists; he thinks the percentage is lower than that. In a test of hypothesis, H₀: p = 0.05 vs. H₁: p < 0.05, his random sample of size 1,000 registered voters revealed that the number of Socialists was 40. -Test the hypotheses at the 5% significance level.

The test statistic for p is approximately normal when np and n(1 - p) are both ____________________.

The 95% confidence interval would indicate that, for this shipment, the proportion of defective fuses is between 0 and 0.28.

If there are two unbiased estimators of the same parameter, the one whose variance is smaller is said to be relatively more ____________________.

Knowing that an estimator is unbiased only assures us that its expected value equals the parameter, but it does not tell us how close the estimator is to the parameter.

After calculating the sample size needed to estimate a population proportion to within 0.04, your statistics professor told you the maximum allowable error must be reduced to just .01. If the original calculation led to a sample size of 800, the sample size will now have to be: