Modern medical practice tells us not to encourage babies to become too fat. Is there a positive correlation between the weight of a 1-year old baby and the weight y of the mature adult (30 years old)? A random sample of medical files produced the following information for 14 females. x (lb) 22 22 y (lb) 126 USE SALT y= be 9m x=300: Dy=1.774; ²6.582: 2225,870: Exy - 38.188 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for and y to bwo decimal places. Round your answers for least-squares estimates to three decimal places.) (b) Draw a scatter diagram for the data. Plot the least-squares line on your scatter diagram. y 160 150 140 Le 130 120 110 O 10 y 160 130 140 130 120 27 20 122 122 124 130 110 O ¹10 15 20 15 24 26 22 19 15 25 1 17 120 145 130 130 130 130 140 110 115 25 20 25 پہر پہر 160 130 140 La 130 120 30 110 O ¹10 160 150 1:40 130 120 110 15 10 15 20 25 30 O (c) Find the sample correlation coefficient and the coefficient of determination. (Round your answers to three decimal places.) 2 what percentage of variation in y is explained by the least-squares model? (Round your answer to one decimal place.) IN (d) If a female baby weighs 21 pounds at 1 year what do you predict she will weigh at 30 years of age? (Round your answer to two decimal places.) lb

• The paper referenced in the previous exercise gave the accompanying data on the at which smoking started for a sample of 1031 men who smoked low-tar cigarettes. 12.8 also age Eregu eno

The average height of 18-year-old American women is 64.2 inches. You wonder whether the mean height of this year's female graduates from your local high school is different from the national average. You measure an SRS of 78 female graduates and find that x⎯⎯⎯x¯ = 63.1 inches. What are your null and alternative hypotheses? Note: Type in "mu" as the substitute for μμ and "!=" for ≠≠. H0:Ha:

An article reported data from a study in which both a baseline gasoline mixture and a reformulated gasoline were used. Consider the following observations on age (yr) and NOx emissions (g/kWh): Engine 1 2 3 4 5 6 7 8 9 10 Age 0 0 2 11 7 16 9 0 12 4 Baseline 1.70 4.38 4.06 1.24 5.29 0.59 3.35 3.45 0.73 1.22 Reformulated     1.86     5.91     5.51     2.70     6.50     0.71     4.95     4.86     0.72     1.41   Construct scatter plots of the baseline NOx emissions versus age.  What appears to be the nature of the relationship between these two variables? There is no compelling relationship between the data. As age increases, emissions also increase.     As age increases, emissions decrease.

To illustrate the effects of driving under the influence (DUI) of alcohol, a police officer brought a DUI simulator to a local high school. Student reaction time in an emergency was measured with unimpaired vision and also while wearing a pair of special goggles to simulate the effects of alcohol on vision. For a random sample of nine teenagers, the time (in seconds) required to bring the vehicle to a stop from a speed of 60 miles per hour was recorded. Complete parts (a) and (b). Note: A normal probability plot and boxplot of the data indicate that the differences are approximately normally distributed with no outliers. Click the icon to view the data table. (a) Whether the student had unimpaired vision or wore goggles first was randomly selected. Why is this a good idea in designing the experiment? A. This is a good idea in designing the experiment because it controls for any "learning" that may occur in using the simulator. B. This is a good idea in designing the experiment because…

A study published by Babcock and Marks (2010) showed that the average full-time U.S. college student studied for μ = 14 hours per week (SD = 4.8 hours per week) in 2005. We want to know if this average has changed in the past 15 years. In other words, we are going to do a study in which we try to determine whether there has been an impact of the passage of time on the amount of time college students spend studying. We selected a sample of n = 64 of today’s college students and find that they spent an average of M = 12.5 hours per week studying. Does this sample indicate a significant change in the number of hours spent studying? Use a two-tailed test (this means non-directional hypothesis) with α = .05.

Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 46 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that ? = 7.40 ml/kg for the distribution of blood plasma. (a)Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.) lower limit__ upper limit__ margin of error__ (b)What conditions are necessary for your calculations? (Select all that apply.) A-the distribution of volumes is normal B-the distribution of volumes is uniform C-? is unknown D-? is known E-n is large (c)Interpret your results in the context of this problem. A-The probability that this interval…

A researcher speculates that because of differences in diet, Japanese children have a lower mean blood cholesterol level than U.S. children do. Suppose that the mean level for U.S. children is known to be 165. Let μ represent the true mean blood cholesterol level for Japanese children. What hypotheses should the researcher test? Ho: μ = 165 versus H₂: μ> 165 a O Ho: μ = 165 versus H₂: μ 165 O Ho: μ = 165 versus H: μ > 155

Ocean currents are important in studies of climate change, as well as ecology studies of dispersal of plankton. Drift bottles are used to study ocean currents in the Pacific near Hawaii, the Solomon Islands, New Guinea, and other islands. Let x represent the number of days to recovery of a drift bottle after release and y represent the distance from point of release to point of recovery in km/100. The following data are representative of one study using drift bottles to study ocean currents. Σx = 476, Σy = 87.1, Σx2 = 62,290, Σy2 = 2046.87, Σxy = 11121.3,and  r ≈ 0.94367. x days        72    76     32   91     205y km/100  14.7 19.6   5.3  11.7  35.8 a) Use a 1% level of significance to test the claim ? > 0.(Use 2 decimal places.)t =critical t= b) Find the predicted distance (km/100) when a drift bottle has been floating for 60 days. (Use 2 decimal places.)________ km/100 c) Find a 90% confidence interval for your prediction of part (d). (Use 1 decimal place.)lower limit = _____…

The data found below measure the amounts of greenhouse gas emissions from three types of vehicles. The measurements are in tons per year, expressed as CO2 equivalents. Use a 0.025 significance level to test the claim that the different types of vehicle have the same mean amount of greenhouse gas emissions. Based on the results, does the type of vehicle appear to affect the amount of greenhouse gas emissions? Click the icon to view the data. What are the hypotheses for this test? O A. Ho: At least one of the means is different from the others. H₁ H₁ H₂ H3 OB. Ho: H₁ H₁: H1 H₂ =H3 H₂ H3 OC. Ho: H₁ H₂ H3 H₁: At least one of the means is different from the others. O D. Ho: H₁ H₂ H3 H₁: H₁ H₂ =H3 Data Table Type A 6.2 6.2 6.5 7.4 7.1 6.1 6.9 7.3 6.9 6.7 Print C Type B 7.7 7.5 8.7 8.1 8.6 8.8 8.4 8.5 Type C 8.5 9.3 9.6 9.1 9.1 9.1 9.8 9.5 9.9 Done O X