POTIC
paring Data - Item 31786
A track coach is trying to improve the 50-meter-dash times of the track
team. He times each student and then implements a month-long
training program. At the end of the program, he timed each of the
students again. The box plots show the number of seconds it took the
students to run the 50-meter-dash before and after the program.
Using the plots, how much did the median change?

At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. the cyclic nature of wind and moving sand determines the shape and location of large dunes. at a test site, the prevailing direction of the wind did not change noticeably. however, the velocity did change. fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. based on long-term experience, σ can be assumed to be 245 cm/sec. (a) find a 95% confidence interval for the population mean wind speed at this site. (round your answers to the nearest whole number.) lower limit cm/sec upper limit cm/sec

Of to(3, 4) (2,1) (3,7) (5,2) (5,-2) (3, 3) (-2, 3) (1,2) (-4,-2) (-3, 1) (4, -1) (-1, 1) 10 v 29

Researchers are conducting experiments to determine the role of alcohol in the development of depression. after the study is complete, they determine that the relative risk of developing depression is 1.55 with a 95 % ci of 1.2 -1.9. each group is then divided into nonsmokers and smokers. the relative risk for the nonsmokers is 1.12 with a 95% ci of 0.87-1.37. the relative risk for the smokers is 1.7 with a 95 % cl of 1.5-1.9. what type of bias may affect this study? a. procedure bias b. recall bias c. selection bias d. confounding e. lead-time bias