Question O Answered step-by-step In a large class in statistics, the final examination grades have a mean of 67.4 and a standard deviation of 12. Q1. the percentage of grades that should exceed 85? Q2 Assuming that the distribution of these grades is normal, find the percentage less than 45. Q3. Assuming that the distribution of these grades is normal, find the number of passes (pass mark is 50) in a class of 180. Q4. Assuming that the distribution of these grades is normal, find the lowest distinction mark if the highest 8% of grades are to be regarded as distinctions. Math Statistics and Probability