Question

Show all your work using the formulas unless stated otherwise. Clearly indicate your answer for each problem. For all hypothesis tests, be sure to define the population parameters and state the null and alternative hypotheses. 1) A research study showed that a sample of 25 dosages from a medicine dispensing machine averaged 24.1 mg of a certain drug. The sample standard deviation was 1.8 mg. a) Form a 99% confidence interval of the population average of drug dosage dispensed. b) Explain what this interval means to someone unfamiliar with this research. 3) In 2001, the U.S. Department of Labor reported the average hourly earnings for U.S. production workers to be $14.32 per hour. A sample of 30 production workers during 2003 showed a sample mean of $14.68 per hour and had a sample standard deviation of $1.45. Can we conclude that an increase occurred in the mean hourly earnings since 2001? Use a = .01. (Carefully set up the hypothesis test first by identifying the null and alternative hypotheses. Clearly indicate the rejection rule. Use rejection region and/or p-value approach.) 2) Consider the following hypothesis test: Ηο: μ≥ 20 Ho is many times written Ho: µ = 20 Ha: μ <20 A sample of 50 provided a sample mean of 19.4. The population standard deviation is 2. Use a.05. a) Compute the critical value (location of end point(s) of rejection region). b) Formulate the rejection rule: "Reject Ho if...". c) What is the value of the test statistic? d) What is the conclusion? e) Another way to come to the same conclusion is to determine the p-value. Formulate the rejection rule in terms of a p-value, determine the p-value and confirm the conclusion. 4) Suppose a current state poll was taken showing that 1,137 individuals out of 1,753 registered voters surveyed would vote for candidate J Barnes in the election. a) Form a 95% confidence interval of the population proportion of registered voters who would vote for Barnes in the election. Explain what this interval is telling you. b) Is the margin of error (sampling error) less than 3%? c) Suppose previous polls from two weeks prior showed essentially 68% of registered voters would vote for Barnes. Is there enough evidence in the current poll to suggest there has been a decrease in the proportion who would vote for Barnes? Formulate a hypothesis test to test this assertion at a level of significance of .01.

Show all your work using the formulas unless stated otherwise. Clearly indicate your answer for
each problem. For all hypothesis tests, be sure to define the population parameters and
state the null and alternative hypotheses.
1) A research study showed that a sample of 25 dosages from a medicine dispensing machine
averaged 24.1 mg of a certain drug. The sample standard deviation was 1.8 mg. a) Form a
99% confidence interval of the population average of drug dosage dispensed. b) Explain
what this interval means to someone unfamiliar with this research.
3) In 2001, the U.S. Department of Labor reported the average hourly earnings for U.S.
production workers to be $14.32 per hour. A sample of 30 production workers during 2003
showed a sample mean of $14.68 per hour and had a sample standard deviation of $1.45. Can
we conclude that an increase occurred in the mean hourly earnings since 2001? Use a = .01.
(Carefully set up the hypothesis test first by identifying the null and alternative hypotheses.
Clearly indicate the rejection rule. Use rejection region and/or p-value approach.)
2) Consider the following hypothesis test:
Ηο: μ≥ 20 Ho is many times written Ho: µ = 20
Ha: μ <20
A sample of 50 provided a sample mean of 19.4. The population standard deviation is 2.
Use a.05.
a) Compute the critical value (location of end point(s) of rejection region).
b) Formulate the rejection rule: "Reject Ho if...".
c) What is the value of the test statistic?
d) What is the conclusion?
e) Another way to come to the same conclusion is to determine the p-value. Formulate
the rejection rule in terms of a p-value, determine the p-value and confirm the
conclusion.
4) Suppose a current state poll was taken showing that 1,137 individuals out of 1,753 registered
voters surveyed would vote for candidate J Barnes in the election.
a) Form a 95% confidence interval of the population proportion of registered voters who
would vote for Barnes in the election. Explain what this interval is telling you.
b) Is the margin of error (sampling error) less than 3%?
c) Suppose previous polls from two weeks prior showed essentially 68% of registered
voters would vote for Barnes. Is there enough evidence in the current poll to suggest
there has been a decrease in the proportion who would vote for Barnes? Formulate a
hypothesis test to test this assertion at a level of significance of .01.

Added by Tracy R.

Question

Please give Ace some feedback