An instructor for a test preparation course claims that the course will improve the test scores of students. The table shows the critical reading scores for 14 students the first two times they took the test. Before taking the test for the second time, the students took the instructor's course to try to improve their critical reading test scores. At a = 0.01, is there enough evidence to support the instructor's claim? Complete parts (a) through (f). Student 1 2 3 4 7 8 10 11 12 13 14 Score on first test 366 449 434375 426 507501 337 347544 428 558 401 410 Score on second test 375515 497 406 381 536 455454 406 596 474 583 441 447

The stem-and-leaf display below gives the test scores for the students in Prof. Ramirez's 10 a.m. and 11 10 a.m. class and 23 students in the 11 a.m. class. Use the display to answer the questions that follow. Test scores for Prof. Ramirez's economics classes 10 a.m. 11 a.m. 9 87 425 8632 589 7775551 06002489 9 854 7 4 55 679 78025578 95 Key: 47 + - 7|4 |2 42 (a) What were the ranges for the two classes? 10 a.m. 11 a.m. (b) Which class had the higher median score? o10 a.m. o11 a.m. OThe medians were the same (c) Which class had more scores in the 50s? 10 a.m. o11 a.m. OEach had the same

The values listed below are waiting times (in minutes) of customers at two different banks. At Bank A, customers enter a single waiting line that feeds three teller windows. At Bank B, customers may enter any one of three different lines that have formed at three teller windows. Answer the following questions. Bank A 6.4 6.6 6.7 6.8 7.1 7.3 7.5 7.7 7.7 7.7 Bank B 4.2 5.5 5.7 6.2 6.7 7.8 7.8 8.5 9.3 10.0 Click the icon to view the table of Chi-Square critical values. Construct a 95% confidence interval for the population standard deviation o at Bank A. min< OBank A min (Round two decimal places as needed.) Construct a 95% confidence interval for the population standard deviation o at Bank B. min < OBank B < min (Round to two decimal places as needed.) Interpret the results found in the previous parts. Do the confidence intervals suggest a difference in the variation among waiting times? Does the single-line system or the multiple-line system seem to be a better arrangement? O A. The…