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(Exercises 27–40) For each description of data, identify the W’s, name the variables, specify for each variable whether its use indicates that it should be treated as categorical or quantitative, and, for any quantitative variable, identify the units in which it was measured (or note that they were not provided).
33. Herbal medicine Scientists at a major pharmaceutical firm conducted an experiment to study the effectiveness of an herbal compound to treat the common cold. They exposed each patient to a cold virus, then gave them either the herbal compound or a sugar solution known to have no effect on colds. Several days later they assessed each patient’s condition, using a cold severity scale
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- Primary data is O a. Always collected before secondary data O b. Usually collected through annual reports O c. Information that already exists o d. Collected for the specific purpose at handarrow_forwardTrying to determine the number of students to accept is a tricky task for universities. The Admissions staff at a small private college wants to use data from the past few years to predict the number of students enrolling in the university from those who are accepted by the university. The data are provided in the following table. R F eTextbook and Media Save for Late O % 5 T O >> G H (9) 2 Number Accepted Number Enrolled Find the correlation between the number of students accepted and enrolled. Use two decimal places in your answer. & 2,440 2,800 2,720 2,360 2,660 2,620 8 6 611 K 708 637 584 614 625 ( 9 L Attempts: 0 of 1 used ) 0 P Submit Answer 56°F Cl Backspaarrow_forwardThe body mass index (BMI) of a person is the person’s weight divided by the square of his or her height. It is an indirect measure of the person’s body fat and an indicator of obesity. Results from surveys conducted by the Centers for Disease Control and Prevention (CDC) showed that the estimated mean BMI for US adults increased from 25.0 in the 1960–1962 period to 28.1 in the 1999–2002 period. [Source: Ogden, C., et al. (2004). Mean body weight, height, and body mass index, United States 1960–2002. Suppose you are a health researcher. You conduct a hypothesis test to determine whether the mean BMI of US adults in the current year is greater than the mean BMI of US adults in 2000. Assume that the mean BMI of US adults in 2000 was 28.1 (the population mean). You obtain a sample of BMI measurements of 1,034 US adults, which yields a sample mean of M = 28.9. Let μ denote the mean BMI of US adults in the current year. Please Formulate the null and alternative hypothesesarrow_forward
- b. An evaluation to study the relationship between quality of sleep and amount of exercises required in order to maintain a healthy lifestyle. Let X be the number of sleeping hours, and Y be the number of hours doing physical activities on weekly basis. The resuilts have been summarized in Table 2 below. Table 2 Y = 6 Y =7Y = 8 Total X= 6 0.05 0.04 0.10 0.19 X=7 0.04 0.16 0.20 0.40 X = 8 0.02 0.09 0.30 0.41 Total 0.11 0.29 0.60 1.00 Find the probability that an individual has fewer physical acțivities than sleeping hours, P(Y < X).arrow_forwardThe following are the cystatin C levels (mg/L) for the patients described in Exercise 15 (A-17).Cystatin C is a cationic basic protein that was investigated for its relationship to GFR levels. In addition, creatinine levels are also given. (Note: Some subjects were measured more thanonce.) Cystatin C (mg/L) Creatinine (mmol/L) 1.78 4.69 0.35 0.14 2.16 3.78 0.30 0.11 1.82 2.24 0.20 0.09 1.86 4.93 0.17 0.12 1.75 2.71 0.15 0.07 1.83 1.76 0.13 0.12 2.49 2.62 0.14 0.11 1.69 2.61 0.12 0.07 1.85 3.65 0.24 0.10 1.76 2.36 0.16 0.13 1.25 3.25 0.17 0.09 1.50 2.01 0.11 0.12 2.06 2.51 0.12 0.06 2.34Source: D. M. Z. Krieser, M.D. Used with permission.(a) For each variable, compute the mean, median, variance, standard deviation, and coefficient ofvariation.(b) For each variable, construct a stem-and-leaf display and a box-and-whisker plot.(c) Which set of measurements is more variable, cystatin C or creatinine? On what do you baseyour answer? that question from…arrow_forwardSam Jones has 2 years of historical sales data for his company. He is applyingfor a business loan and must supply his projections of sales by month for thenext 2 years to the bank. a. Using the data from Table 6–12, provide a regression forecast for timeperiods 25 through 48.b. Does Sam’s sales data show a seasonal pattern?arrow_forward
- Data was collected for a sample of organic snacks. The amount of sugar (in mg) in each snack is summarized in the histogram below. Which statement best describes the meaning of one of the bars in the histogram? Frequency 10 8 6 4 2 ✓ 200 220 240 260 280 300 320 340 amount of sugar (mg) 3 snacks have about 210 mg of sugar. The largest number of snacks have 11 mg of sugar 210 snacks have 3 mg of sugar. 210 snacks have between 200 and 220 mg of sugar. Score: 0/1 Time spent on this version: 6.5 minutes.arrow_forwardAnswer 4 5 6 7arrow_forwarda. Which data set has a larger variation? (justify your answer)b. Is Chebyshev' rule verified for these two data sets. (Justify your answer graphically).c. What can we conclude?arrow_forward
- State if these variables would be expected to have a positive, negative, or no association. A. Number of schools and population size. o Positive Negative No association B. Income and number of health conditions. Positive o Negative No association C. Time spent meditating and stress level. Positive o Negative No association D. Number of pets and amount of money spent on printer ink. Positive Negative o No association E. Life expectancy and death rate. Positive Negative o No associationarrow_forwardFind the principal components of the data for Exercise 2. Reference Exercise 2: 5 2 6. 3 11 3 11 6. 15 ["arrow_forwardUsing the data in Table 6–11, answer the following:a. What is the slope?b. What is the intercept?c. Write the regression equation.d. Calculate a regression forecast for month 25.arrow_forward
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