2. For a data set obtained from a random sample, n = 81 and x = 48.25. It is known
that σ = 4.8.
- What is the point estimate of μ? Round to two decimal places
- Make a 95% confidence interval for μ. What is the lower limit? Round to two decimal places.
- Make a 95% confidence interval for μ. What is the upper limit? Round to two decimal places.
- What is the margin of error of estimate for part b? Round to two decimal places.
3. Determine the sample size (nfor the estimate of μ for the following.
- E = 2.3, σ = 15.40, confidence level = 99%. Round to the nearest whole number.
- E = 4.1, σ = 23.45, confidence level = 95%. Round to the nearest whole number.
- E = 25.9, σ = 122.25, confidence level = 90%. Round to the nearest whole number.
4. True or False.
a.The null hypothesis is a claim about a population parameter that is assumed to be false until it is declared false.
A. True
B. False
b. An alternative hypothesis is a claim about a population parameter that will be true if the null hypothesis is false.
A. True
B. False
c. The critical point(s) divide(s) is some of the area under a distribution curve into rejection and nonrejection regions.
A. True
B. False
d. The significance level, denoted by α, is the probability of making a Type II error, that is, the probability of rejecting the null hypothesis when it is actually true.
A. True
B. False
e. The nonrejection region is the area to the right or left of the critical point where the null hypothesis is not rejected.
A. True
B. False
5. You are given the null hypothesis. Select the correct alternative hypothesis.
a) H0:μ=9.5hours, what is H1?
A. left-tailed test
B. right-tailed test
C. two-tail test
b) H0:μ =$105, what is H1?
A. left-tailed test
B. right-tailed test
C. two-tail test
c) H0:μ=$47,000,what is H1?
A.left-tailed test
B. right-tailed test
C. two-tail test
d) H0:μ=10minutes, what is H1?
A. left-tailed test
B. right-tailed test
C. two-tail test
e) H0:μ=30hours, what is H1?
A. left-tailed test
B. right-tailed test
C. two-tail test
7. Consider H0: μ = 45 versus H1: μ < 45. A random sample of 25 observations produced a sample mean of 41.8. Using α = .025 and the population is known to be normally distributed with σ = 6.
- What is the value of z? Round to two decimal places.
- Would you reject the null hypothesis?
-
- Reject Ho
- Do not reject Ho
8. The following information is obtained from two independent samples selected from two normally distributed populations.
n1 = 18 x1 = 7.82 σ1 = 2.35
n2 =15 x2 =5.99 σ2 =3.17
A. What is the point estimate of μ1 − μ2? Round to two decimal places.
B. Construct a 99% confidence interval for μ1 − μ2. Find the margin of error for this estimate.
Round to two decimal places.
9. The following information is obtained from two independent samples selected from two
populations.
n1 =650 x1 =1.05 σ1 =5.22
n2 =675 x2 =1.54 σ2 =6.80
Test at a 5% significance level if μ1 is less than μ2.
a) Identify the appropriate distribution to use.
- t distribution
- normal distribution
b) What is the conclusion about the hypothesis?
A. Reject Ho
B. Do not reject Ho
10. Using data from the U.S. Census Bureau and other sources, www.nerdwallet.com estimated that considering only the households with credit card debts, the average credit card debt for U.S. house- holds was $15,523 in 2014 and $15,242 in 2013. Suppose that these estimates were based on random samples of 600 households with credit card debts in 2014 and 700 households with credit card debts in 2013. Suppose that the sample standard deviations for these two samples were $3870 and $3764, respectively. Assume that the standard deviations for the two populations are unknown but equal.
a) Let μ1 and μ2 be the average credit card debts for all such households for the years 2014 and 2013, respectively. What is the point estimate of μ1 − μ2? Round to two decimal places. Do not include the dollar sign.
b) Construct a 98% confidence interval for μ1 − μ2. Round to two decimal places. Do not include the dollar sign.
-
- What is the lower bound? Round to two decimal places.
- What is the upper bound? Round to two decimal places.
c) Using a 1% significance level, can you conclude that the average credit card debt for such households was higher in 2014 than in 2013? Use both the p-value and the critical-value approaches to make this test.
A. Reject Ho
B. Do not reject Ho
Our Service Charter
-
Excellent Quality / 100% Plagiarism-Free
We employ a number of measures to ensure top quality essays. The papers go through a system of quality control prior to delivery. We run plagiarism checks on each paper to ensure that they will be 100% plagiarism-free. So, only clean copies hit customers’ emails. We also never resell the papers completed by our writers. So, once it is checked using a plagiarism checker, the paper will be unique. Speaking of the academic writing standards, we will stick to the assignment brief given by the customer and assign the perfect writer. By saying “the perfect writer” we mean the one having an academic degree in the customer’s study field and positive feedback from other customers. -
Free Revisions
We keep the quality bar of all papers high. But in case you need some extra brilliance to the paper, here’s what to do. First of all, you can choose a top writer. It means that we will assign an expert with a degree in your subject. And secondly, you can rely on our editing services. Our editors will revise your papers, checking whether or not they comply with high standards of academic writing. In addition, editing entails adjusting content if it’s off the topic, adding more sources, refining the language style, and making sure the referencing style is followed. -
Confidentiality / 100% No Disclosure
We make sure that clients’ personal data remains confidential and is not exploited for any purposes beyond those related to our services. We only ask you to provide us with the information that is required to produce the paper according to your writing needs. Please note that the payment info is protected as well. Feel free to refer to the support team for more information about our payment methods. The fact that you used our service is kept secret due to the advanced security standards. So, you can be sure that no one will find out that you got a paper from our writing service. -
Money Back Guarantee
If the writer doesn’t address all the questions on your assignment brief or the delivered paper appears to be off the topic, you can ask for a refund. Or, if it is applicable, you can opt in for free revision within 14-30 days, depending on your paper’s length. The revision or refund request should be sent within 14 days after delivery. The customer gets 100% money-back in case they haven't downloaded the paper. All approved refunds will be returned to the customer’s credit card or Bonus Balance in a form of store credit. Take a note that we will send an extra compensation if the customers goes with a store credit. -
24/7 Customer Support
We have a support team working 24/7 ready to give your issue concerning the order their immediate attention. If you have any questions about the ordering process, communication with the writer, payment options, feel free to join live chat. Be sure to get a fast response. They can also give you the exact price quote, taking into account the timing, desired academic level of the paper, and the number of pages.