Independent random samples of professional football and basketball players gave the following information. Assume that the weight distributions are mound-shaped and symmetric. Weights (in Ib) of pro football players: x,; n, = 21 243 262 256 251 244 276 240 265 257 252 282 256 250 264 270 275 245 275 253 265 270 Weights (in Ib) of pro basketball players: x,; n, = 19 204 200 220 210 193 215 222 216 228 207 225 208 195 191 207 196 182 193 201 In USE SALT (a) Use a calculator with mean and standard deviation keys to calculate x,, S,, X2, and s3. (Round your answers to four decimal places.) x =[ X2 = s2 = (b) Let u, be the population mean for x, and let u, be the population mean for x,. Find a 99% confidence interval for u, - Hz. (Round your answers to one decimal place.) lower limit upper limit (c) Examine the confidence interval and explain what it means in the context of this problem. Does the interval consist of numbers that are all positive? all negative? of different signs? At the 99% level of fessionall foothall plavers tend to bave a higber population mean than haskethall nlavers?

Ensure the RaceResults worksheet is active, then use the FREQUENCY function to calculate the frequency distribution of the race results in column D. Place your results in the range G4:G9. Enter a function in cell F22 to calculate the correlation between age (Columns C) and race time (Column D). Enter a function in cell G22 to calculate the covariance between age and race time. Enter a function in cell H22 to calculate the variance of the ages in the data set. Note this is a sample of data not a population. Enter a function in cell 122 to calculate the standard deviation of the ages in the data set.

The following data represent petal lengths (in cm) for independent random samples of two species of iris. Petal length (in cm) of Iris virginica: x1; n1 = 36 5.2 5.6 6.1 6.1 5.1 5.5 5.3 5.5 6.9 5.0 4.9 6.0 4.8 6.1 5.6 5.1 5.6 4.8 5.4 5.1 5.1 5.9 5.2 5.7 5.4 4.5 6.4 5.3 5.5 6.7 5.7 4.9 4.8 5.8 5.2 5.2 Petal length (in cm) of Iris setosa: x2; n2 = 38 1.6 1.8 1.4 1.5 1.5 1.6 1.4 1.1 1.2 1.4 1.7 1.0 1.7 1.9 1.6 1.4 1.5 1.4 1.2 1.3 1.5 1.3 1.6 1.9 1.4 1.6 1.5 1.4 1.6 1.2 1.9 1.5 1.6 1.4 1.3 1.7 1.5 1.5   (a) Use a calculator with mean and standard deviation keys to calculate x1, s1, x2, and s2. (Round your answers to four decimal places.) x1=s1=x2=s2= (b) Let μ1 be the population mean for x1 and let μ2 be the population mean for x2. Find a 99% confidence interval for μ1 − μ2. (Round your answers to two decimal places.) lower limitupper limit

3.  Can SAT scores predict college performance?  Let x be a variable that represents SAT score of a computer science major, and let y be a variable that represents a student’s GPA upon graduation.  A random sample of n =15 computer science majors provided their SAT scores and GPAs: x 1232 1070 1086 1287 1130 1048 1121 1095 1135 1208 1333 1160 1186 1243 1261 y 3.52 2.91 2.4 3.47 3.47 2.37 2.4 2.24 3.02 3.32 3.59 2.54 3.19 3.71 3.58   The scatter diagram for the SAT score and GPA is given below:   (a)  Find the sample correlation coefficient r.  Truncate to two decimal places.  What does the value tell you about the data? (b)  Find the equation of the least squares line .  Truncate to four decimal places.  What does the slope mean? (c)  Find the value of the coefficient of determination .  Truncate to two decimal places.  What does this number mean? (d)  What is the predicted GPA if a computer science major got a…

Independent random samples of professional football and basketball players gave the following information. Assume that the weight distributions are mound-shaped and symmetric. Weights (in lb) of pro football players: x1; n1 = 21 245 263 254 251 244 276 240 265 257 252 282 256 250 264 270 275 245 275 253 265 272 Weights (in lb) of pro basketball players: x2; n2 = 19 205 200 220 210 193 215 221 216 228 207 225 208 195 191 207 196 183 193 201 (a) Use a calculator with mean and standard deviation keys to calculate x1, s1, x2, and s2. (Round your answers to four decimal places.) x1 =   s1 =   x2 =   s2 =   (b) Let ?1 be the population mean for x1 and let ?2 be the population mean for x2. Find a 99% confidence interval for ?1 − ?2. (Round your answers to one decimal place.) lower limit       upper limit       (c) Examine the confidence interval and explain what it means in the context of this problem. Does the interval consist of numbers that are all…

Independent random samples of professional football and basketball players gave the following information. Assume that the weight distributions are mound-shaped and symmetric. Weights (in lb) of pro football players: x1; n1 = 21 247 263 256 251 244 276 240 265 257 252 282 256 250 264 270 275 245 275 253 265 272 Weights (in lb) of pro basketball players: x2; n2 = 19 202 200 220 210 192 215 221 216 228 207 225 208 195 191 207 196 182 193 201 (a) Use a calculator with mean and standard deviation keys to calculate x1, s1, x2, and s2. (Round your answers to four decimal places.) x1 =   s1 =   x2 =   s2 =   (b) Let μ1 be the population mean for x1 and let μ2 be the population mean for x2. Find a 99% confidence interval for μ1 − μ2. (Round your answers to one decimal place.) lower limit       upper limit       (c) Examine the confidence interval and explain what it means in the context of this problem. Does the interval consist of numbers that are all…

Let x be the average number of employees in a group health insurance plan, and let y be theaverage administrative cost as a percentage of claims. The following data is based on a randomsample:x 5 7 15 25 35y 40 35 30 20 25a. Plot a scatter diagram of the above data.b. Estimate the sample correlation coefficient r as positive, zero, or negative.c. Interpret your results from parts a. and b.

The following table presents the daily high temperatures for the city of Macon, Georgia, in degrees Fahrenheit, for the winter months of January and February in a recent year. 58 51 71 58 59 67 52 73 64 64 58 67 53 53 63 75 76 61 52 52 68 67 48 55 69 63 58 56 56 63 74 65 57 53 48 70 76 51 65 60 61 Send data to Excel Construct a stem-and-leaf plot, using the digits 4, 5, 6, and 7 as the stems. Do not separate the answers with a comma. If there are no leaves, select the "None" button. 4 None 5 5 6 7 8 ME ›

Independent random samples of professional football and basketball players gave the following information. Assume that the weight distributions are mound-shaped and symmetric. Weights (in lb) of pro football players: x1; n1 = 21 243 261 254 251 244 276 240 265 257 252 282 256 250 264 270 275 245 275 253 265 271 Weights (in lb) of pro basketball players: x2; n2 = 19 204 200 220 210 193 215 222 216 228 207 225 208 195 191 207 196 183 193 201   (a) Use a calculator with mean and standard deviation keys to calculate x1, s1, x2, and s2. (Round your answers to four decimal places.) x1 =   s1 =   x2 =   s2 =   (b) Let ?1 be the population mean for x1 and let ?2 be the population mean for x2. Find a 99% confidence interval for ?1 − ?2. (Round your answers to one decimal place.) lower limit       upper limit       (c) Examine the confidence interval and explain what it means in the context of this problem. Does the interval consist of numbers that are all…