A business school claims that students who complete a three month course of typing course can type on average, at least 1200 words an hour. A random sample of 25 students who completed this course typed, on average, 1130 words an hour with a standard deviation of 85 words. Assume that the typing speeds for all students who complete this course have an approximate normal distribution. Using the 5% significance level, can you conclude that the claim of the business school is true?
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!
3. A business school claims that students who complete a three month course of typing
course can type on average, at least 1200 words an hour. A random sample of 25
students who completed this course typed, on average, 1130 words an hour with a
standard deviation of 85 words. Assume that the typing speeds for all students who
complete this course have an approximate
significance level, can you conclude that the claim of the business school is true?
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