Let XB and XA denote, respectively, the weight of a person before and after a certain weight loss diet regime. If D = XA- XB, then the mean of the differences, D, calculated on a random sample of size n, can be used as a basis to test Ho: µD = 0 against H1: µD > 0 and thus verify if the weight loss diet has been effective. A t-test statistic is usually built as the ratio of an estimator of the population parameter of interest (or a function of the population parameters of interest in the case of the difference of two means), divided by its standard error. A significant treatment-by-block interaction in the ANOVA for an RCBD with more than one replicate per treatment per block indicates that differences among treatments are not constant from block to block.

The Cadet is a popular model of sport utility vehicle, known for its relatively high resale value. The bivariate data given below were taken from a sample of fifteen Cadets, each bought new two years ago, and each sold used within the past month. For each Cadet in the sample, we have listed both the mileage x (in thousands of miles) that the Cadet had on its odometer at the time it was sold used and the price y (in thousands of dollars) at which the Cadet was sold used. The least-squares regression line for these data has equation y = 40.86-0.45x. This line is shown in the scatter plot below. Mileage, x (in thousands) 29.7 27.8 26.8 24.2 21.1 23.0 24.3 15.4 37.7 23.6 34.4 27.8 23.5 20.9 259 Used selling price, y (in thousands of dollars) 27.4 29.4 31.2 30.1 31.7 31.7 27.2 34.2 23.4 28.2 26.3 26.5 33.7 30.6 267 Used selling price (in thousands of dollars) 40- 35+ 30- 25- 20 THIS 15 X 20 X X X 30 Mileagex (in thousands) X 35 40

The weight of cereal boxes (y) follows a normal distributed with a variance of 0.1 squared ounces. If the average is 15.8 ounces, then P(y < 16) = If the average is 16.5 ounces, then P(y > 16.2)

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 ? = 7.80 ml/kg for the distribution of blood plasma. (d) Find the sample size necessary for a 99% confidence level with maximal margin of error E = 2.90 for the mean plasma volume in male firefighters. (Round up to the nearest whole number.) ________ male firefighters

A food manufacturer claims that eating its new cereal as part of a daily diet lowers total blood cholesterol levels. The table shows the total blood cholesterol levels (in milligrams per deciliter of blood) of seven patients before eating the cereal and after one year of eating the cereal as part of their diets. Use technology to test the mean difference. Assume the samples are random and dependent, and the population is normally distributed. At a = 0.05, can you conclude that the new cereal lowers total blood cholesterol levels? Patient Total Blood Cholesterol (Before) Total Blood Cholesterol (After) OA. Ho Hd #0 HA Hd=0 OC. Ho Hd ≤0 HA Hd >0 Calculate the standardized test statistic t= (Round to three decimal places as needed.) Calculate the P-value P-value= (Round to four decimal places as needed) State the conclusion. 1 205 204 Ho. There C 2 225 222 Let the blood cholesterol level before eating the cereal be population 1. Let the blood cholesterol level after eating the cereal be…

Devise a hypotheses for the research question:  Is there singificant correlation between students height and typical amount of sleep a student gets per night?  Identify the appropriate statistical test using alpha = 0.05. Perform the statistical test. Use descriptive statistics to describe the variables both numerically and graphically. Height (whole inches) Sleep (minutes) 60 360 62 400 66 420 68 440 68 540 70 480 72 320 75 440 66 360 63 420 69 420 75 390 69 360 67 480 69 360 73 360 69 480 70 420 68 360 63 480 69 270 68 360 71 420 71 360 62 420

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 4.6 parts/million (ppm). A researcher believes that the current ozone level is at an excess level. The mean of 14 samples is 4.9 ppm with a variance of 1.2 Does the data support the claim at the 0.01 level? Assume the population distribution is approximately normal. Step 2 of 5 :   Find the value of the test statistic. Round your answer to three decimal places.

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 44 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 ? = 7.20 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.) the distribution of volumes is normal ? is known the distribution of volumes is uniform n is large ? is unknown c) Find the sample size necessary for a 99% confidence level with maximal margin of error E = 2.80 for the mean plasma…

(c) Calculate the test statistic.

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 42 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 ? = 8.00 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 limitupper limitmargin of error (b) What conditions are necessary for your calculations? (Select all that apply.) the distribution of volumes is uniform? is knownn is largethe distribution of volumes is normal? is unknown (c) Interpret your results in the context of this problem. We are 99% confident that the true average blood…