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Hypothesis Testing

Important Applications of Statistical Concepts

Summarize the most important applications of statistical concepts and discuss why these particular concepts are important for decision makers. a. When you create and implement a strategic plan, how would you measure the success of that strategy? b. If you see improvement, how will you know that it is significant? Consider sca

Various Hypothesis Testing Problems

Diabetes The insulin pump is a device that delivers insulin to a diabetic patient at regular intervals. It presumably regulates insulin better than standard injections. However, data to establish this point are few, especially in children. The following study was set up to assess the effect of use of the insulin pump on HgbA

The solution gives detailed steps on performing a chi-square test for checking independence for multiple groups. Also, another chi-square test using expected frequency technique is shown and explained.

I need to know which equation to use and detailed steps to answer the following question by hand. The following data were collected in a clinical trial evaluating a new compound designed to improve wound healing in trauma patients. The new compound is compared against a placebo. After treatment for 5 days with the new comp

Hypothesis vs. Theory

Please help understand these questions: 1) What is the difference between hypothesis and theory? If there is a difference between the two, what comes first - hypothesis or theory? 2) Why is it important to test a hypothesis? Give the rationale. Can we conduct research without hypothesis testing? Can you think of an example

Hypothesis Testing for Two Samples

I need help solving the following problems: In this problem set you will get some practice performing hypothesis tests for two samples. If you use Statdisk to perform any portion of these analyses, please include the results, label them, and refer to them accordingly in your interpretations. Good luck and enjoy! 1. Ten

Statistics Practice Problems

1) The health of employees is monitored by periodically weighing them in. A sample of 54 employees has a mean weight of 183.9 lb. Assuming that σ is known to be 121.2 lb, use a 0.10 significance level to test the claim that the population mean of all such employees weights is less than 200 lb. Identify the null hypothesis, alt

Hypothesis Testing for a Single Mean: Fat Content of Hamburgers

See the attached file. 1. The fat content was determined for 40 hamburgers sold by a fast food restaurant. The results in grams appear below. 20.0 18.7 21.6 20.9 21.8 20.2 19.7 18.9 19.5 21.5 19.3 21.2 18.4 21.0 21.6 20.6 20.7 21.9 20.1 17.1 18.1 21.1 19.3 21.5 20.1 16.5 18.9 17.4 20.8 18.5 21

Average salary of blue-collar workers

While negotiating a labor contract, the president of a company argues that the mean annual earnings of blue-collar workers is less than $56,000. The labor union argues that the salary is more than $56,000. A random sample of the annual earnings of 350 blue-collar workers is taken and contained in the file LaborDispute.xls.

Private colleges in U.S. revealing endowments

4. Private colleges and universities rely on money contributed by individuals and corporations for their operating expenses. Much of this money is put into a fund called an endowment. A college or university spends only the interest earned by the fund. A recent survey of 8 private colleges in the United States revealed the follo

Webcredible

Webcredible, a UK-based consulting firm specializing in websites, intranets, mobile devices, and applications, conducted a survey of 1,132 mobile phone users between February and April 2009. The survey found that 52% of mobile phone users are now using the mobile Internet. (Data extracted from "Email and Social Networking Most P

Determine The Degrees of Freedom Within And Between Group

I need help finding the degrees of freedom. Can you show me how to get it step bye step without using Excel? (between group and within group) Four different paints are advertised as having the same drying time. To check the manufacturer's claims, five samples were tested for each of the paints. The time in minutes until the p

Test a claim and STATDISK

(1) Assume that head injury measurements are not affect by an interaction between type of car (foreign, domestic) and size of car (small, medium, large). Is there sufficient evidence to support the claim that size of the car has an effect on head injury measurements? Use display 1 which results from the head injury measurem

Using the "Traditional" and "P-Value" Method for Hypotheses

In both "traditional" and "p- value" method: A simple random sample of 40 recorded speeds(in mi/h) is obtained from cars traveling on a section of highway 405 in Los Angeles. The simple random sample has a mean of 68.4mi/h and a standard deviation of 5.7mi/h. Use a 0.05 significance level to test the claim that the mean speed of

The solution gives detailed steps of hypothesis testing on mean difference using the example of market research firm. All formula and calculations are shown. Finally, conclusion is stated clearly.

P 21 A market research firm used a sample of individuals to SELFIII rate the purchase potential of a particular product before and after the individuals saw a new television commercial about the product. The purchase potential ratings were based on a 0 to 10 scale, with higher values indicating a higher purchase potential. T

The solution gives detailed steps on performing a hypothesis tesing for population proportion using the example of Eagle Outfitters. All 5-steps, formula and calculations are shown and explained.

Eagle Outfitters is a chain of stores specializing in outdoor apparel and camping gear. It is considering a promotion that involves mailing discount coupons to all its credit card customers. This promotion will be considered a success if more than 10% of those receiving the coupons use them. Before going national with the promot

Predictors of Salary

Suppose you went to the Bureau of Labor Statistics web site and found several predictors of your salary. State three possible predictors and a simulated multilinear regression equation along with their p-values. What does your p-values tell you about your predictors?

Hypothesis Testing and Scatter Plots

I need help (step-by-step) with the following questions for my upcoming test. (please see attached). Please explain the process of figuring these questions out. I have an upcoming final and I need to know how to do these problems. A random sample of eight quarterback listed in The Sports Encyclopedia: Pro Football, gave the f

Concluding Mean Waiting Time and Premium Rate

The Internal Revenue Service (IRS) provides a toll-free help line for taxpayers to call in and get answers to questions as they prepare their tax returns. In recent years, the IRS has been inundated with taxpayer calls and has redesigned its phone service as well as posted answers to frequently asked questions on its website (Th

Significance level testing: Paying Bills Online

Over the past few years, banks have strongly promoted online banking and the paying of bills online. In 2003, about 50% of internet users paid bills online. In a recent survey of 250 internet users, 150 said that they pay bills online. At the 5% level of significance, test whether the proportion of internet users paying bills on

Hypotheses Based on P-Value and Level of Significance

3. A survey taken showed that among 785 randomly selected subjects who completed 4 years of college, 144 smoke and 641 do not smoke (based on data from the American Medical Association). Use the 0.01 level of significance to test the claim that the rate (proportion) of smoking among those with four years of college is less tha

Computing Value of Test Statistic

Consider the following hypothesis test: Ho: u > 20 (( their is a line under this sine >)) Ha: u < 20 A sample of 50 provided a sample mean of 19.4. The population standard deviation is 2. a. Compute the value of the test statistic. b. What i

Miscellaneus Statistics Questions

1. Assume there are 20 homes in the Quail Creek area and 10 of them have a security system. Four homes are selected at random: (a) What is the probability all four of the selected homes have a security system? (Round your answer to 4 decimal places.) (b) What is the probability none of the four selected homes have a security

The solution gives detailed steps to calculation the point estimate of population mean and standard deviation. Also, the probabilities in a sample with known sample mean and standard deviation are computed step by step.

1. A simple random sample of five months of sales data provided the following information Month 1 2 3 4 5 Units Sold 94 100 85 94 92 a. Develop a point estimate of the population mean number of units sold per month. b. Develop a point estimate of the population standard deviation 2. The College Board reported the f

Statistics: Hypothesis and Error Types

In a specific company, there are three levels of workers: skilled, unskilled, and manager. The owner of this company wants to know if the level of job satisfaction differs amongst the three levels of workers. Data: 30 workers in each level are randomly selected to take the job satisfaction survey. The survey asks each worker

Significance Level Dependent Variables

1. A researcher collected data from 28 individuals. Seven independent variables were used to predict a dependent variable. The value of R2 for this model was .87. When the variable X_1 and X_3 were omitted from the model, R^2 was .84. Do the variables X1 and X3 contribute to the prediction of the dependent variable? Use a .10 si

Conclude is Performance is Independent of Time of Shift

Suppose that the medical staff indicates that the results of a given laboratory procedure must be available 30 minutes after the physician submits a request for the service. In this situation, if the results arrived 30 minutes or less after the request, we regard the performance of the laboratory as timely. If results arrived mo

Statistics: computerized tutorial center

A computerized tutorial center at a local college wants to compare two different statistical software programs. Students going to the center are matched with other student having similar abilities in statistics (assume the matching process creates matched pairs acceptable for use with the appropriate paired test statistic for t

Critical Thinking Statistical Analysis of an Article

Critical Thinking Concept Review 1. Choose three peer C-reviewed research articles and write a short review of each of them that includes the following: a. Write the problem statement. b. Name the theoretical model used or briefly describe the overall conceptual model. c. Write out the main research questions. What is the ra

HYPOTHESIS TESTING: Null Hypothesis Relative to Problem and Decision.

In your environment (business or personal), please describe a hypothesis test related to a decision. What would be your data? What would be your null hypothesis? What would be your alternate hypothesis? What would be your Type 1 and Type 2 errors relative to your decision? Suppose you have a p-value of 0.01, what does this mean