Question 1 Which one of the following statements is true to perform a z-test for the difference between two population mean μ1 and μ2? a. Three conditions are required to perform such a test. b. The samples must be independent and selected randomly. c. Sample size must be at least 30. d. All of the above. Ques
A computer manufacturer offers a help line that purchasers can call for help 24 hours a day, 7 days a week. Clearing these calls for help in a timely fashion is important to the company's image. After telling the caller that resolution of the problem is important the caller is asked whether the issue is "software" or "hardware"
Question 1 Multiple Choice In testing hypotheses, the researcher initially assumes: the alternative hypothesis is true. the null hypothesis is true errors cannot be made the population parameter of interest is known Question 2 Multiple Choice The rejection and non rejection regions are divid
1. Suppose you are working with a data set that is normally distributed with a mean of 400 and a standard deviation of 20. Determine the value of x such that only 1% of the values are greater than x. 353.4 446.6 405 400.039 2. When the rod shearing process at Stockton Steel is "in control" it produces rods
1. If x is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then P(x 24) is __________________. 0.000 0.600 0.333 0.100 2. Consider the following null and alternative hypotheses. H0: μ 7 Ha: μ> 6 These hypotheses _______________. are not collectively exhaustive
1. Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks. One of her standard's is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans. Last Friday's sample c
What is the importance of hypothesis testing for independence of variables using two-way tables? Is there an example of this for a better understanding?
1. For any normal distribution, any value less than the mean would have a _______. a) negative probability of occurring b) negative z-score c) positive z-score d) negative variance 2. The diameter of 3.5 inch diskettes is normally distributed. Periodically, quality control inspectors at Dallas Diskettes randomly se
? Description of data analysis procedures o Selection/justification of your basic statistical approach o Test(s) of assumptions underlying the statistical approach o Any modification made based on your test(s) of assumptions ? Description of findings o Summary table comparing groups o Accompanying narrative stateme
How do we go about interpreting the results of various types of statistical tests in health care research?
Statistics Study Questions: Multiple choice questions on t distribution, z distribution, hypothesis, chi-squared distribution, confidence level, margin of error, critical value, degrees of freedom, sample size
Question 1 Which level of confidence would produce the widest confidence interval? A. 98% B. 90% C. 95% D. 99% Question 2 What is the margin of error if c = 0.9, s = 1.5, n = 50 A. 1.645 B. 0.1 C. 0.349 D. 0.049 Question 3 For a sample less than 30 we can use t-distribution only if A. The population is nor
A manager hopes to improve the sales figures for 10 employees by sending them to a motivational seminar. To test the effectiveness of this seminar, the manager compares the sales figures for each salesperson for the month immediately prior to the seminar and the month immediately following it. Employee before after H
For the following set of data, test the hypothesis that the average is 10. Run a test of that hypothesis and present the conclusion. x 8.9 9.7 10.3 8.5 10.4 9.3 9.8 7.1 10.6 11.1
Why do statisticians shudder at the word "prove" and use words like support, accept the H1, and reject the Ho etc.?
What is a "p" value and why do we need it? (Hint: What does it give us in addition to our alpha?)
Explain the difference between a 1 and a 2 tailed test. When is each used?
1. Compute the critical values for a 2-tailed z-test with alpha = 0.01. Explain your answer. Sample mean = 78.47 Population mean = 75.8 Population standard deviation = 7.5 Standard error of the sample mean = .898 n= 100 2. We had to determine the critical value of z to make our accept/reject decision; In this analysis
A door manufacturer wants to monitor the performance of a new painting process, which has been designed to apply paint with a mean thickness of 0.7mm, by detecting any departure from this target. One hundred doors will be randomly chosen from a day's production, and the thickness of paint on each of the 100 doors will be measure
At .05 significance level, is there a difference in the distribution of heart attacks based on the amount smoked?
Note: Assume the condition of Normality is met for problem below. A study is made of men over the age of 50. Each man is classified as to whether or not he has had a heart attack and the amount that he smokes at the present time. The following results were obtained for a sample of 300 men. Heart Attack Amount smoked
Attached is a 5 step hypothesis test. I have tried to work through this and am stuck on step 4 and 5. I am not 100% sure I am using the correct test statistic and am totally lost on step 4. This test is being done on only one sample. The sample is below: 2.05 2.06 2.07 2.07 2.08 2.11 2.14 2.15 2.16 2.17 2.18 2.
1) Perform the five-step hypothesis test on your data. 2) Describe the results of your tests and compare the results to the results of the test performed for your previous Hypothesis Testing Paper. See attached files for full additional information.
Use the probabilities determine what percentage purchased Total at least twice. Is age category independent of willingness to try new products? What is the probability that a randomly selected person purchased Total given that the person is in the 45-64 age category?
In the mid-1990s, Colgate-Palmolive had developed a new toothpaste for the U.S. market, Colgate Total, with an antibacterial ingredient that was already being successfully sold overseas. However, the word antibacterial was not allowed for such products by the Food and Drug Administration rules. So Colgate-Palmolive had to come
See attached file for full problem description. Problem 1 You own a radio station and you have three salespeople. Below is a listing of their sales for the last eight weeks. Please use α .05 to decide if there is a difference in the means. Problem 2 Research the area where you live, or any other city you like. Fin
Use a type 1 error rate of 0.05 to determine if the two chemicals are different with respect to their effectiveness. Construct an appropriate 95% confidence interval for the experimental results. State your conclusions.
A pesticide control company wants to compare the effectiveness of two pest control chemicals (call then A and B) with respect to their ability to kill ants. An experiment is conducted as follows: 2000 ants are selected at random. 1000 are selected and placed in a room labeled A The remaining 1000 are placed in a room la
1. When we say we have a confidence level of 95%, what do you think our "margin of error" is? 2. If we move the level of confidence from 95 to 99%, what will happen to our margin of error? What will happen to the width of our confidence interval? 3. Would we have gotten a better feel for the amount of flour needed if we'd
1. Using the internet (or other outside source), research a health related variable such as newborn weight or heart rate (although you may not use these since they have already been discussed in class). Based on the information you discover (such as mean, median, typical range, etc.), would you say that your variable has a norm
There used to be an ad on TV that claimed one toothpaste was proven to be more effective in fighting tooth decay than another. One of statistics professors was interested in the study, and after 6 ads finally got the address to write away for it from the TV. The study was classically perfect - randomly assigned individuals i
I need to write an evaluation of a research article (article attached). It needs to include a brief description of the article and follow a systematic approach. Article attached -- it tests the hypothesis that attitudes towards HIV/AIDS will improve after participation in an educational program.
What are the theoretical considerations of hypothesis testing and why are these considerations important when conducting research studies? Define statistical comparisons, correlations and predictions as they relate to social science research. What role do they play in the data collection process?
The following data resulted from a taste test of two different chocolate bars. The first number is a rating of the taste, which could range from 0 to 5, with a 5 indicating the person liked the taste. The second number indicates whether a "secret ingredient" was present. If the ingredient was present a code of "1" was used, and