1- In a study investigating the effect of car speed on accident severity, 5000 reports of fatal automobile accidents were examined, and the vehicle speed at impact was recorded for each one. For these 5000 accidents, the average speed was 43 mph and that the standard deviation was 17 mph. A histogram revealed that the vehicle speed at impact distribution was approximately normal. (a) Roughly what proportion of vehicle speeds were between 26 and 60 mph? (Round the answer to the nearest whole number.) Approximately % (b) Roughly what proportion of vehicle speeds exceeded 60 mph? (Round the answer to the nearest whole number.) Approximately % 2- A student took two national aptitude tests. The national average and standard deviation were 325 and 100, respectively, for the first test and 30 and 8, respectively, for the second test. The student scored 425 on the first test and 45 on the second test. Use z scores to determine on which exam the student performed better relative to the other test takers. first exam second exam 3-The average reading speed of students completing a speed-reading course is 450 words per minute (wpm). If the standard deviation is 80 wpm, find the z score associated with each of the following reading speeds. (Round the answers to two decimal places.) 300 wpm 465 wpm 400 wpm 590 wpm