Distribution of exam scores follows the normal distribution, with a mean of 70 percent and a standard deviation of 10. a) What percent of students scored 85 percent or higher on the exam? b) What was the lowest grade of the students scoring the top five percent of the scores? c) What was the percentage of students earning between 75 and 85 percent on the exam?
Continuous Probability Distributions
Probability distributions are of two types, which are continuous probability distributions and discrete probability distributions. A continuous probability distribution contains an infinite number of values. For example, if time is infinite: you could count from 0 to a trillion seconds, billion seconds, so on indefinitely. A discrete probability distribution consists of only a countable set of possible values.
Normal Distribution
Suppose we had to design a bathroom weighing scale, how would we decide what should be the range of the weighing machine? Would we take the highest recorded human weight in history and use that as the upper limit for our weighing scale? This may not be a great idea as the sensitivity of the scale would get reduced if the range is too large. At the same time, if we keep the upper limit too low, it may not be usable for a large percentage of the population!
Distribution of exam scores follows the
a) What percent of students scored 85 percent or higher on the exam?
b) What was the lowest grade of the students scoring the top five percent of the scores?
c) What was the percentage of students earning between 75 and 85 percent on the exam?
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