Explanation for Question 7 From the Math (Calc) Section on the 2018 May Sat
Question seven says an analysis of a random sample of a type of laptop, 2 computer battery, estimated that the mean working time was 4.7 hours 3 with a margin of error of 0.7 hours, 4 which of the following is the most appropriate conclusion based on this analysis. 5 So we know that the mean is 47 plus or minus 0.7, 6 which means that the mean is less than or equal to 5.4 7 and greater than or equal to four point up, 8 which tells us that the answer is C that this type of laptop, 9 computer battery has a mean working time of between four and 5.4 10 hours.