A set of final examination grades in an introductory statistics course is normally distributed, with a mean of 79 and a standard deviation of 7. Complete parts (a) through (d). a. What is the probability that a student scored below 91 on this exam? The probability that a student scored below 91 is 0.9564 (Round to four decimal places as needed.) b. What is the probability that a student scored between 72 and 997 The probability that a student scored between 72 and 99 is 0.8392 (Round to four decimal places as needed.) c. The probablity is 25% that a student taking the test scores higher than what grade? The probability is 25% that a student taking the test scores higher than 84 (Round to the nearest integer as needed) d. If the professor grades on a curve (for example, the professor could give A's to the top 10% of the class, regardless of the score), i a student better off with a grade of 93 on the exam with a mean of 79 and a standard deviation of 7 or a grade of 70 on a different exam where the mean is 66 and the standard deviation is 47 Show your answer statistically and explain. A student is with a grade of 93 on the exam with a mean of 79 and a standard deviation of 7 because the Z value for the grade of 93 is and the Z value for the grade of 70 on the different exam is (Round to tw needed) better off worse off