Swimsuits A swimsuit manufacturer wants to test thespeed of its newly designed suit. The company designs an experiment by having 6 randomly selected Olympic swim-mers swim as fast as they can with their old swimsuit first and then swim the same event again with the new, expen-sive swimsuit. The company will use the difference in times as the response variable. Criticize the experiment and pointout some of the problems with generalizing the results.

man loves, as everyone should, to collect and analyze statistical information. He wishes to find a relationship between how many hours students study and how they do on their statistics tests.  He takes a random sample of 16 students at Ideal U., asks how many hours they studied for a university-wide stat test and how they did on the test, enters the data into a computer for analysis and presents the results below.   ANALYSIS OF HOURS AND GRADES (n = 16):   Descriptive Statistics:   HOURS GRADES Mean:  4.2  75.8 Mode:  5.0  79.0 St. Dev:  2.3  10.1   Quartiles: Q0  2.0  34.0 Q1  3.2  53.7 Q2  4.7  78.5 Q3  6.3  86.9 Q4  9.0  97.0   Regression Analysis: Reg. Eq. is: GRADE = 16.9 + 9.025*HOURS Rsquared = .985 std error = 0.027   F = 8.52 p = .018   We know that 25% of all the grades falls into which of these regions?     a. 78.5 to 79.0   b. 78.5 to 86.9     c. 75.8 to 86.9     d. 75.8 to 97.0     e. 78.5 to 97.0   f. 75.8 to 79.0

A company uses an automated process in checking for defective electronic devices that they manufacture. For devices that are defective, 98% of them will be labeled as defective. Three percent of the devices that are okay (not defective) will be labeled as defective. Four percent of the devices made by this company are defective.   _____________________ percent of devices that are labeled as defective are not defective.

researcher would like to examine the effect of fertilizer on flower growth. She obtains several flowers. She randomly assigns half the plants to the no fertilizer condition. The other half of the plants receive fertilizer. She monitors their growth for a month. She then compares the amount of growth of the two sets of plants. Is there a difference in growth between the no fertilizer and the fertilizer conditions? Use the .05 level of significance. In addition, find Cohen’s d and state what the effect size is in a sentence. Growth Rating No Fertilizer 40,21,27,30, 47 Fertilizer 46,25, 24, 38, 53

You need to use Stata to look up the dataset and its variables. Use Stata Companion Textbook. (Dataset: NES. Variables: spend8, [pw=nesw].) The NES dataset contains spend8, which records the number of government policy areas where respondents think spending should be increased. Scores range from 0 (the respondent does not want to increase spending on any of the policies) to 8 (the respondent wants to increase spending on all eight policies). The NES, of course, polls a random sample of U.S. adults. In this exercise you will analyze spend8 using the mean and lincom commands. You then will draw inferences about the population mean. (Remember to specify nesw as the probability weight.) The spend8 variable has a sample mean of ______. Make sure you use [pw=nesw] so your results are nationally representative. There is a probability of .95 that spend8’s true population mean falls between a score of ______ at the low end and a score of ______ at the high end. A student researcher…

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Allergic reactions to poison ivy can be miserable. Plant oils cause the reaction. Researchers at Allergy Institute did a study to determine the effects of washing the oil off within 5 minutes of exposure. A random sample of 1000 people with known allergies to poison ivy participated in the study. Oil from the poison ivy plant was rubbed on a patch of skin. For 500 of the subjects, it was washed off within 5 minutes. For the other 500 subjects, the oil was washed off after 5 minutes. The results are summarized in the following table. Reaction Within 5 Minutes After 5 Minutes Row Total NoneMildStrong 4025543 64323113 466378156 Column Total 500 500 1000 Let's use the following notation for the various events: W = washing oil off within 5 minutes, A = washing oil off after 5 minutes, N = no reaction, M = mild reaction, S = strong reaction. Find the following probabilities for a person selected at random from this sample of 1000 subjects. (Use 3 decimal places.)   (d) P(N and…

The boxplot below shows salaries for CPAS and Actuaries in a town. СРА Actuary 20 30 40 50 60 70 80 90 100 110 Salary (thousands of $) If a person is making the third quartile salary for a CPA, they are making less than % of Actuaries.

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ge 2: Has the proportion of Americans that are "20-somethings" decreased? According to the US Census Bureau, 14.8% of Americans living in 2004 were "20- somethings" (between ages 20 and 29). You take a random sample of 500 Americans and find that 59 of them fall in this age range. Has the proportion of Americans ages 20-29 decreased from what it was in 2004? for this problem (z-test or t-test).