at position 10 10 Multiple Choice 4 points Question at position 10 A letter is drawn from the alphabet of 26 letters. What is the probability that the letter drawn is a vowel? 21/26 1/26 5/26 4/26 Question at position 11 11 Multiple Choice 3 points Question at position 11 A car wash loses $30 on rainy days and makes $120 on days when it does not rain. If the probability of rain is 0.15, calculate expected profit for the car wash. $97.50 $90 $106.50 $76.50 Question at position 12 12 Multiple Choice 4 points Question at position 12 The exact spread of the t distribution depends on the ________. Number of degrees of freedom Sample size n z distribution Standard deviation of the sample Question at position 13 13 Multiple Choice 4 points Question at position 13 Health insurers and the federal government are both putting pressure on hospitals to shorten the average length of stay (LOS) of their patients. In 1996, the average LOS for non-heart patients was 4.6 days. A random sample of 20 hospitals in one state had a mean LOS for non-heart patients in 2000 of 3.8 days and a standard deviation of