(b) The percentage results in a Maths exam for a class had a mean mark of 70 with a standard deviation of 15. The percentage results in an English exam for the same class had a mean mark of 72 with a standard deviation of 10. The results in both exams were normally distributed. (i) Mary got 65 in Maths and 68 in English. In which exam did Mary do better relative to the other students in the class? Justify your answer. ݖଵ Answer: Justification: 0

Suppose the scores on an exam are normally distributed with a mean μ = 75 points, and standard deviation σ = 8 points.The instructor wanted to "pass" anyone who scored above 69. What proportion of exams will have passing scores? 0.1587 0.75 0.2266 0.7734 −0.75

Heidi and John are teachers teaching similar classes and both gave their classes an exam.  Here are the summaries for the exam scores:Heidi's class:Mean 75Median 78Standard Deviation 3John's class:Mean 75Median 65Standard Deviation 12 Which of the following statements is most correct?  Group of answer choicesJohn's class had some students who received very low scores, exactly 50% of his students scored less than or equal to 75%, and the scores were quite varied when compared to Heidi's class scores.John's class likely had some outlier scores that were very high, exactly 50% of his students scored less than or equal to 65%, and the scores were quite varied when compared to Heidi's class scores.The scores in John's class were more consistent than the scores in Heidi's class.Since the median is higher than the mean in Heidi's class, there were likely some outlier scores that were very high.John's class likely had some outlier scores that were very high and thus the mean would be the best measure of center for his data set.

Question 10Drs. Melnyk and Ahmed conducted a study in which 400 participants completed a 50-point test about their knowledge of statistics. The mean score was 40 with a standard deviation of 5. These results approximated a normal distribution, which means that the probability of a score between 0 and 1 standard deviations was about 34.1%, between 1 and 2 standard deviations was about 13.6%, and above 2 standard deviations was about 2.3%. If Ashley’s score on this test was 50, what percentage of students are below Ashley’s score? 1 point97.7%13.6%99.8%47.7%

Sue took a test in both biology and math last week. The biology test had a mean of 70 and a standard deviation of 7, whereas the math test had a mean of 75 and a standard deviation of 10. Sue scored a 76 on the biology test and a 76 on the math test. On which test did she do better in comparison to the rest of the class?Choose onethe math testthe biology testShe did the same on each test.cannot be determined

In a Statistics test, the average mark is 82 and the standard deviation is 5. All the students from 88 marks up to 94 marks will receive a B grade. If the marks have a normal distribution and 8 students receive B grade, determine the total number of students who sat for the test.