1.) Below are students' SAT scores before and after taking a prep course: Before 1200 1190 890 1380 1280 1170 1170 1090 890 After 1300 1090 1090 1500 1340 1500 1200 1180 1090 At a = 0.01, test the claim that the mean difference of scores is below zero, meaning that the course improves SAT scores. Is the prep course effective? a.) Use a hypothesis test b.) Use an appropriate confidence interval 2.) Below are cellular data speeds from Sprint and Verizon measured at different airports. Sprint 13.0 30.4 15.2 2.4 2.7 2.1 0.8 1.6 5.6 Verizon 38.5 55.6 22.4 14.1 23.1 24.5 6.5 21.5 25.7 a.) Calculate r and determine if there is linear correlation. State the critical value. b.) If there is linear correlation, find the regression line. If not, skip this step. c.) LAX has Sprint speed of 10.2. Predict Verizon's speed at LAX. 3.) Data below lists actual and predicted high temperatures for ten different random days. Actual 80 77 81 85 73 73 80 72 83 81 Predicted 56 57 59 56 64 57 61 63 59 61 a.) Calculate r and determine if there is linear correlation. State the critical value. b.) If there is linear correlation, find the regression line. If not, skip this step. c.) If the actual high in this place was 70, what was the predicted high? 4.) 120 community college students were asked if they rent their calculator for their Statistics class, and 86 said they do. Out of 150 university students, 70 said they rent theirs. At a = 0.05, is the proportion of community college students higher than university students? Test: a.) Use a hypothesis test b.) Use an appropriate confidence interval 5.) Below are prices per gallon of regular gasoline at various Shell and Mobil gas stations. Shell: $3.34 $3.56 $3.45 $3.90 $4.01 $4.12 $3.36 $3.59 Mobil: $23.24 $3.25 $3.99 $3.99 $4.33 $2.99 $3.23 $2.90 $3.56 $3.12 At a = 0.01, test the claim that these two gas chains have the same average gas prices. a.) Use a hypothesis test b.) Use an appropriate confidence interval