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
I recently completed a survey concerning whether or not cell phone usage on airplanes will lead to air rage or not. I have the results from the survey in excel fomat but I am not sure how to complete a one tailed t test for the questions. I am trying to show the surveyed people say that they wii become irritated by prolonged cel
Answer questions about hypothesis tests. For questions 3 and 4, do a complete hypothesis test and state your conclusions.
See the attachments for the complete descriptions of the questions. 1.) A toy manufacturer claims that the mean time that its top-selling toy captures children's attention is at least 35 minutes. Suppose that we doubt this claim and we carry out a hypothesis test to see if we can refute the claim. State the null hypothesis
Let's say you want to know if the amount of candy adults eat influences the number of times they brush their teeth in a day. Your independent variable is candy - you will manipulate how many pieces of candy they eat. Your dependent variable is the number of times they brush their teeth in a day. This is a ratio scale: they can b
Comparing the means of two populations. What is the value of the test statistic? What is the conclusion?
Please see sample problem in attachment. --- Consider the following hypothesis test H0: mu1 - mu2 = 0 Ha: mu1 - mu2 =/ 0 The following results are for two independent samples taken from the two populations. Sample 1 Sample 2 n1 = 80 n2 = 70 mu1 = 104 mu2 = 106 s1 = 8.4 s2
I have to do a paper that would identify a research issue, problem, or opportunity that uses data that has absolute zero measurements, such as interval and ratio level data. I chose the temperature in my city over the course of a month, what would be the issue, problem or opportunity with weather over the course of a month. I ne
The Holland wood company manufacturers and assembles desks and other office equipment at several plants in Michigan. The weekly production of the Model A3 desk at the Grand Rapids Plant is normally distributed with a mean of 200 and a standard deviation of 16. Recently, due to market expansion, new production methods have be
I have 2 samples that I must compare using the 5% level of risk. Population One - Sample Size 45, mean income $31,290, SD $1,060 Population Two - Sample Size 60, mean income $31,330, SD $1,900 I would assume that I would run a Chi-Square for independent means but I need the population variance do I not before I can do any
I have to identify a research issue, problem, or opportunity that uses data that has absolute zero measurements, such as interval and ratio level data. What if I choose the temperature in my city over the course of a month. What would be the issue, problem or opportunity with weather over the course of a month?
We want to test the claim that the Smith method of gender selection is effective in increasing the likelihood that a baby will be born a girl. In a random sample of 80 couples who use the Smith method, it is found that among the 80 newborn babies, there are 35 girls. What should we conclude about the claim? Why is it nece
Tom Smith wants to test the hypothesis that adult men have a mean weight that is greater than 150 pounds. Tom surveys the adult male members of his family and obtains 40 sample values, which lead him to support the alternative hypothesis that the population mean is greater than 150 pounds. What is the fundamental flaw in hi
I love filet mignon. The full cut is supposed to weigh 16 ounces when fully cooked. My restaurant serves 200 servings of filet mignon per day. The restaurant claim is they serve filets that are 16 ounces with a standard deviation of .4 ounces due to shrinking while cooking. I ate filet mignon for 16 days straight. The average we
Taking a trip to Sweden again. Last years statistics report showed that 65% of the entire adult population are women. I had a friend in Sweden take a poll to see if this was true. He picked 50 adults at random and reported that 36 of them were female. Is it possible that the proportion of women is different than what I read in t
1) The manufacturer of the X-15 steel-belted radial truck tire claims that the mean mileage the tire can be driven before the tread wears out is 60,000 miles. The standard deviation of the mileage is 5,000 miles. The Crosset Truck Company bought 48 tires and found that the mean mileage for their trucks is 59,500 miles. Is Crosse