FROM: Chapter on Statistical Inference Concerning Two Populations (Data set and excel formula workbook for problem attached)The Speedo LZR Racer Suit is a high-end body-length swimsuit that was launched in February 2008. Wehn 17 world records fell at the December 2008 Short Course Championships in Croatia, many believed a modification in the rules surrounding swimsuits was necessary. The FINA Congress, the international governing board for swimming, banned the LZR Racer and all other body-length swimsuits from competition effective Jan 2010. In a statement to the public, FINA defended its position with the following statement: “FINA wishes to recall the main and core principle that swimming is a sport essentially based on the physical performance of the athlete”.Luke Johnson, a freelance journalist, wonders if the decision made by FIJNAhas statistical backing. He conducts an experiment with the local university’s Division I swim team. He times 10 of the swimmers swimming the 50 Meter breaststroke in his bathing suit and then retests them while wearing the LZR Racer. A portion of the results are shown int he accompanying table (see attached excel for dataset).1.) In a report (using the attached excel formulas) determine whether the LZR Racer significantly improves swimmers times at the 5% significance level. Assume that the time difference is normally distributed.2.) Comment on whether the data appear to support FINAs decision.
The accompanying table shows annual return data from 2001-2009 for Vanguard’s Balanced Index and European Stock Index mutual funds.(excel attached) A. )Set up the hypotheses to test whether the mean returns of the two funds differ. (Hint: This is a matched -pairs comparison) B.)At the 5% level of significance, determine if the mean weight gain of women due to pregnancy is more than 35 pounds.
By using a computer algorithm, an investigator can assign members of twin pairs at random to an intervention condition in a clinical trial. Assume that each twin pair consists of dizygotic twins (one male and one female). The probability of assigning one member of the pair to the intervention condition is 50%. Among the first four pairs, what is the probability of assigning to the intervention condition: 1) zero females, 2) one female, 3) two females, 4) three females, 4) four females?
he article “Why We Fall for This” (AARP Magazine, May/June 2011) described a study in which a business professor divided his class into two groups. He showed students a mug and then asked students in one of the groups how much they would pay for the mug. Students in the other group were asked how much they would sell the mug for if it belonged to them. Surprisingly, the average value assigned to the mug was quite different for the two groups! Indicate whether the study is an observational study or an experiment. Give a brief explanation for your choice.
Table 4.16 shows results of an eight-center clinical trial to compare a drug to placebo for curing an infection. At each center, subjects were randomly assigned to groups. a. Analyze these data, describing and making inference about the group effect, using logistic regression.
Project Questions have been attached. Two Separate Questions
A study of 800 homeowners in a certain area showed that the average value of the homes was $82,000, and the standard deviation was $5000. If 50 homes are for sale, find the probability that the mean o
The January 1986 mission of the Space Shuttle Challenger was the 25th such shuttle mission. It was unsuccessful due to an explosion caused by an O-ring seal failure. According to NASA, the probability of such a failure in a single mission was 1/600. Suppose the mission was attempted 25 times.a. Find the mean number of mission failures. Include the appropriate symbol.b. Find the variance of the total number of mission failures. Include the appropriate symbol.c. Find the standard deviation of the total number of mission failures. Include the appropriate symbol.
Penguins diving A study of king penguins looked for a relationship between how deep the penguins dive to seek food and how long they stay under water.31 For all but the shallowest dives, there is a linear relationship that is different for different penguins. The study gives a scatterplot for one penguin titled “The Relation of Dive Duration (y) to Depth (x).” Duration y is measured in minutes and depth x is in meters. The report then says, “The regression equation for this bird is: = 2.69 + 0.0138x.” (a) What is the slope of the regression line? Interpret this value. (b) Does the y intercept of the regression line make any sense? If so, interpret it. If not, explain why not. (c) According to the regression line, how long does a typical dive to a depth of 200 meters last? (d) Suppose that the researchers reversed the variables, using x = dive duration and y = depth. What effect will this have on the correlation? On the equation of the least-squares regression line?
. The audio pan pot circuit of Fig. is used to continuously vary the position of signal Vi between the left and the right stereo channels. Determine the relation between R1 and R2 so that ? ???? ???? = -1 when the wiper is fully down, ? ???? ???? = -1 when the wiper is fully up, and ? ???? ???? = ? ???? ???? = 1 2 when the wiper is halfway