A 2003 study found that Americans exercised a mean of 115 minutes per week. A more recent study found that a sample of 20 Americans exercised a mean of 120 minutes per week with a standard deviation of 12 minutes. Can you conclude that the mean number of exercise per week is currently more than 115 minutes per week? a. Use a 0.05 significance level. Assume that the mean number of minutes of exercise is normally distributed. b. If a is changed to 0.01, does your conclusion change?
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!
A 2003 study found that Americans exercised a
a. Use a 0.05 significance level. Assume that the mean number of minutes of exercise is
b. If a is changed to 0.01, does your conclusion change?
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
