18 1.5 points A certain university believes that the average number of students taking Introductory Statistics will Increase from the current level of 400 students per semester, So: X = # of students taking Stats Ho: H = 400 Ha: H > 400 Suppose the data lead the university to conclude that the average number of students is not increasing, and so they decide to maintain the number of sections and instructors they currently have. Which of the following conclusions did they draw? O they rejected Ho O they neither failed to reject Ho nor did they reject Ho O they failed to reject Ho they both rejected Ho and failed to reject Ho 19 1.5 points The lengths of dogs tails are normally distributed with a mean of 8.3 inches and a standard deviation of 2.1 inches. To find the probability that a sample of 12 dogs would have a mean tail length that is more than 10 inches, what standard deviation would you use in your z-score calculation? O 3.464 O 12 O .606 O .175 O 2.1 20 1.5 points A study was conducted to investigate the relationship between the number of miles driven by a family per week y and the number of children in the family x. From the data collected the equation of the least squares regression line was y = 100 + 10x and the correlation coefficient was r= .8. What would be the estimated number of miles driven per week for a family with 3 children? O 330 O can't be determined O 100 O 300 O 130 21 1.5 points * = the number of automobiles requiring repairs Y = the number of automobiles not requiring repairs 20% of the automobiles inspected at a state inspection station required repairs to meet the inspection standard. Five drivers arrive for auto inspections. Find the probability that exactly three automobiles will require repair. .0102 O .0128 .2048 .0512 O .8