If the correlation coefficient (r) is positive, when one variable decreases, the other variable:

a) stays the same.

b) decreases.

c) is unpredictable. We also need to know the strength of the assocation.

d) increases.

Data was collected for homes for sale in Mesa County as of January 2011. Information on the listings such as price, size of the home, and style were recorded.

136500 136500 136500 167900 319000 699000 445000 274000 119900 219900 149900 205000 279000 160000 189900 305000 347000 129900 184500 289900 126900 199000 199900 209000 259000 185000 399900 379000 924500 129000 199900 259000 224900 219900 109900 324900 150000 219900 139900 259000 136000 112000 1475000 199000 289000 159900 127900 199900 295000 275000 199000 212900 359000 289000 179000 159900 199000 164900 129900 255900 165000 174500 235900 229000 499999 539900 239900 269900 280000 139900 139900 195000 135000 107000 177000 199500 276900 149900 115000 142900 142900 139900 142900 330000 164900 125000 134500 119900 184900 399000 154900 895000 155000 109900 107900 151000 154000 169000 349000 236000 169900 102000 179900 129000 135900 169900 369000 259900 209900 105000 239000 192000 415000 189900 112000 349900 102000 159000 174900 190000 239000 269900 190000 249900 109000 339000 249500 139500 221000 176900 249900 124900 96900 155000 235000 104900 137000 199900 249900 309000 124900 119900 111500 204900 369000 128000 128000 399900 183500

3 3 3 30 6 2 6 2 75 14 5 4 3 32 10 4 2 34 4 32 1 6 2 2 2 4 7 3 4 80 1 4 2 32 26 3 60 6 1 17 5 6 18 45 11 38 2 2 6 90 24 5 3 45 6 32 33 42 20 3 1 70 6 4 3 8 4 4 60 50 32 32 5 5 40 1 7 35 35 0 0 0 0 1 12 5 15 33 7 5 27 4 65 2 0 1 1 1 4 4 40 7 12 3 58 33 4 7 4 5 3 6 12 12 4 2 7 40 7 8 2 5 33 33 6 5 2 31 10 7 4 60 7 36 32 6 34 36 31 9 2 5 5 0 6 2 2 4 2

Create a scatterplot of the price of homes (listprice) compared with how old the homes are (age). Select the answer that best describes the data illustrated in the scatterplot.

a) linear with a moderate negative association.

b) linear with a moderate positive association.

c) linear with a strong negative association.

d) nonlinear.

Researchers studying health body composition recorded various measurements of 252 male subjects. Height, weight, age, and other measurements were collected on each subject. For this exercise we will look at the height of the subjects compared with their weight.

154.25 173.25 154 184.75 184.25 210.25 181 176 191 198.25 186.25 216 180.5 205.25 187.75 162.75 195.75 209.25 183.75 211.75 179 200.5 140.25 148.75 151.25 159.25 131.5 148 133.25 160.75 182 160.25 168 218.5 247.25 191.75 202.25 196.75 363.15 203 262.75 205 217 212 125.25 164.25 133.5 148.5 135.75 127.5 158.25 139.25 137.25 152.75 136.25 198 181.5 201.25 202.5 179.75 216 178.75 193.25 178 205.5 183.5 151.5 154.75 155.25 156.75 167.5 146.75 160.75 125 143 148.25 162.5 177.75 161.25 171.25 163.75 150.25 190.25 170.75 168 167 157.75 160 176.75 176 177 179.75 165.25 192.5 184.25 224.5 188.75 162.5 156.5 197 198.5 173.75 172.75 196.75 177 165.5 200.25 203.25 194 168.5 170.75 183.25 178.25 163 175.25 158 177.25 179 191 187.5 206.5 185.25 160.25 151.5 161 167 177.5 152.25 192.25 165.25 171.75 171.25 197 157 168.25 186 166.75 187.75 168.25 212.75 176.75 173.25 167 159.75 188.15 156 208.5 206.5 143.75 223 152.25 241.75 146 156.75 200.25 171.5 205.75 182.5 136.5 177.25 151.25 196 184.25 140 218.75 217 166.25 224.75 228.25 172.75 152.25 125.75 177.25 176.25 226.75 145.25 151 241.25 187.25 234.75 219.25 118.5 145.75 159.25 170.5 167.5 232.75 210.5 202.25 185 153 244.25 193.5 224.75 162.75 180 156.25 168 167.25 170.75 178.25 150 200.5 184 223 208.75 166 195 160.5 159.75 140.5 216.25 168.25 194.75 172.75 219 149.25 154.5 199.25 154.5 153.25 230 161.75 142.25 179.75 126.5 169.5 198.5 174.5 167.75 147.75 182.25 175.5 161.75 157.75 168.75 191.5 219.15 155.25 189.75 127.5 224.5 234.25 227.75 199.5 155.5 215.5 134.25 201 186.75 190.75 207.5

Height 67.75 72.25 66.25 72.25 71.25 74.75 69.75 72.5 74 73.5 74.5 76 69.5 71.25 69.5 66 71 71 67.75 73.5 68 69.75 68.25 70 67.75 71.5 67.5 67.5 64.75 69 73.75 71.25 71.25 71 73.5 65 70 68.25 72.25 67 68.75 69.5 70 71.5 68 73.25 67.5 71.25 68.5 66.75 72.25 69 67.75 73.5 67.5 72 68 69.5 70.75 65.75 73.25 68.5 70.25 67 70 67.5 70.75 71.5 69.25 71.5 71.5 68.75 73.75 64 65.75 67.5 69.5 68.5 70.25 69.25 67.75 67.25 72.75 70 69.25 67.5 67.25 65.75 72.5 73 70 69.5 70.5 71.75 74.5 77.75 73.25 66.5 68.25 72 73.5 72 71.25 73.75 69.25 68.5 73.5 74.25 75.5 69.25 68.5 70 70 70.25 71.75 69.25 72.75 72 74 72.25 74.5 71.5 68.75 66.75 66.5 67 68.75 67.75 73.25 69.75 71.5 70.5 73.25 66.75 69.5 69.75 70.75 74 71.25 75 71 69.5 67.75 72.25 77.5 70.75 72.75 69.75 72.5 70.25 69 74.5 72.25 67.25 73.5 75.25 69 72.25 68.75 71.5 72.25 73 68.75 70.5 72 73.75 68 72.25 69.5 69.5 67.75 65.5 71 71.5 71.75 69.25 67 71.5 69.25 74.5 74.25 68 67.25 69.75 74.25 71.5 74.25 72 72.5 68.25 69.25 76 70.5 74.75 72.75 68.25 69 71.5 72.75 67.5 70.25 69.25 71.5 74 69.75 73 65.5 72.5 70.25 70.75 68 74.5 71.75 70.75 73 64 69.75 70 71.75 69.25 70.5 72.25 67.5 67.25 68.75 66.75 68.25 74.25 69.5 68.5 65.75 71.75 71.5 67.25 67.5 67.5 72.25 69.5 69.5 65.75 65.75 68.25 72 72.75 68.5 69.25 70.5 67 69.75 66 70.5 70

Compute the sample correlation coefficient of the height compared with the weight. Give your answer accurate to three decimal places.

Answer:

Create a scatterplot using these two variables. Using this scatterplot and referring to the correlation coefficient above, select the answer that best describes the data illustrated in the scatterplot.

a) linear with a moderate negative association.

b) linear with a moderate positive association.

c) linear with a strong negative association.

d) nonlinear.

The entrance rate into a presitigous university's graduate program is 13%. A statistics student wants to know if the entrance rate of applicants from Harvard is great than the typical entrance rate. He decides to conduct a hypothesis test of one proportion to determine whether the entrance rate of Harvard student into the graduate program is higher than13%. He randomly selects 60 students who have applied and records whether or not each studen was admitted. Were the requirements for the hypothesis test met?

a) yes, there were more than 5 measurements.

b) yes, there were more than 30 measurements.

c) yes, NP>=10 and n(1-p)>=10.

d) yes, sample proportions always follow a normal distribution.

e) no, np<10

f) no, n(1-p)<10.

g) no, sample proportions never follow a normal distribution.

A factory makes components used in jet engines, including reinforced steel washers. The washers are required to have a very precise thickness. The thickness of the washers follow a normal distribution with mean 1.59 millimeters and standard deviation 0.042 millimeters. A technician randomly samples n = 20 washers and calculates the mean of their thicknesses, which is barx. What is the probability that barx < 1.57?

a. 0.017 b. 0.042 c. 0.317 d. 0.683 e. 0.958 f. 0.983

Parents of children with developmental disorders can apply for federal funding for psychosocial rehabilitation. A government sociologist wants to know what percentage of applicants for this funding are in poverty. She obtains access to all their applications, groups the applications by state, and takes a simple random sample from each state's applications. Identify the population of interest to the sociologist.

Applicants for the federal funding who were in poverty

Applicants for the federal funding

Applicants who received the federal funding

Applicants whose applications were examined

Which sampling scheme was used by the sociologist of the previous question?

Cluster sampling

Convenience sampling

Simple random sampling

Stratified sampling

Systematic sampling

She calculates the percentage of applicants in her sample that are in poverty. Is this percentage a parameter or a statistic, and why?

a parameter, because she examined every applicant.

a parameter, because she only examined the applicants she selected.

a statistic, because she examined every applicant.

a statistic, because she only examined the applicants she selected.