Lysann Damish and her colleagues (2010) wanted to find out if belief in luck improved performance.  They recruited 28 students (using random selection) who were then randomly assigned to be in one of two groups.  Both groups were asked to perform a 10-trial putting task where the goal was to put a golf ball into a cup that was situated 100 cm (39.37 inches) away.  Group 1 was the “lucky” group.  This group was told that the golf ball they were using had been “a lucky ball” in previous tests.  The second group was simply handed to golf ball and asked to put (the “neutral” group).  The number of successful putts in 10 trials was counted for each group. What statistical test should be used and why?

According to DATAUSA, the homeownership rate in Wilmington, DE is 60%. A random sample of 25 residents in Wilmington, DE was selected. The standard error of the proportion is ________.

In a​ survey, it was found that 80​% of adults operate the flusher of toilets in public restrooms with their foot. ​(a) If 300 adults are randomly​ selected, how many would we expect to flush toilets in public restrooms with their​ foot? ​(b) Would it be unusual to observe 270 adults who flush toilets in public restrooms with their​ foot? ​

An observational study is described. Identify the specified element.At St. Luke's hospital in 1998, 674 women were diagnosed with breast cancer. Five years later, 88% of the Caucasian women and 83% of the African American women were still alive. Determine the nature and scope of the conclusion the study can reach. Choose the best answer below: A. Since there is no random assignment, there is no way to know that being Caucasian causes women with breast cancer an increased chance of surviving five years; there may have been confounding variables. B. For women with breast cancer, being Caucasian causes an increased chance of surviving five years. C. Since there is no random assignment, there is no way to know that being Caucasian causes women with breast cancer an increased chance of surviving five years; there may have been lurking variables. D. For Caucasian and African American women with breast cancer, attending St. Luke's hospital causes an increased chance of surviving five…

A new weight-reducing technique, consisting of a liquid protein diet, is currently undergoing tests by the Food and Drug Administration (FDA) before its introduction into the market. The weights of a random sample of five people are recorded before they are introduced to the liquid protein diet. The five individuals are then instructed to follow the liquid protein diet for 3. weeks. At the end of this period, their weights (in pounds) are again recorded. The results are listed in the table. Person Weight Before Diet Weight After Diet 1 165 160 2 210 207 3 203 202 4 216 208 220 217 5 (1) Is there a significant difference between the means of the weights before and after the diet? Use a 0.05

It’s assumed that students need to stay awake more to study during finals week.  One way to measure this is how much coffee is consumed during Finals week at night.  A local coffee house near APU counted the number of cups of coffee sold per hour during Finals week after 6 p.m.  We randomly select ten (10) hours of sales records during Finals week and find out that the following number of cups of coffee were consumed: 18, 17, 22, 14, 17, 20, 22, 24, 15, 15 By comparison, the sales records from a previous week were used as a comparison.  The following number of cups of coffee were consumed over a seven (7) hour period: 9, 13, 5, 15, 17, 10, 11 a. Determine what is the appropriate statistical procedure, with a brief explanation (one sentence) as to why this is the appropriate procedure. b. State the null hypothesis. c. Execute the proper calculations with the appropriate procedures. d. Present a graph when appropriate of your results. e. Include any appropriate post-hoc tests. f. State…

Many fundraisers ask for donations using email and text messages. A paper describes an experiment to investigate whether the proportion of people who make a donation when asked for a donation by email is different from the proportion of people who make a donation when asked for a donation in a text message. In this experiment, 1.7% of those who received and opened an email request for a donation and 7.8% of those who received a text message asking for a donation actually made a donation. Assume that the people who received these requests were randomly assigned to one of the two groups (email or text message) and suppose that the given percentages are based on sample sizes of 2,000 (the actual sample sizes in the experiment were much larger). (Let p1 be the proportion who make a donation after receiving an email, and p2 be the proportion who make a donation after receiving a text message.) Find the test statistic and P-value. (Use a table or SALT. Round your test statistic to two…

In a memory test, the test subjects are given a large number and are asked to memorize it. Historical records show that 80% of test subjects pass the test. To pass the test, a subject must exactly repeat all the digits in the number after two hours. A random sample of 625 people to take the memory test is going to be chosen. Let p be the proportion of people in the sample who pass the test. Answer the following. (If necessary, consult a list of formulas.) (a) Find the mean of P. 0 (b) Find the standard deviation of p. 0 (c) Compute an approximation for P(P >0.84), which is the probability that more than 84% of the people in the sample pass the test. Round your answer to four decimal places. 0 X

2. In a population it is estimated that 20% have a desired trait of interest for the researcher. The researcher wants to know how many people on average he has to draw from a population to get 2 people with the trait. Use rows 20-24 of the Random Number Table to carry out the simulation. Explain clearly how you set up the problem and report your findings. Answer:

You have been asked to estimate the proportion of households in Chicago that have two or more vehicles.   a) How many households would you need to sample to be within 2 percent of the proportion of all households in Chicago that have two or more vehicles at a 90% level of confidence.     b) You conduct a small preliminary sample, and you obtain a sample proportion of 19.5% that have two or more cars. Using this new information, what sample size should you gather in order to be within 2 percent of the proportion of all households in Chicago that have two or more vehicles at a 90% level of confidence.