Question 3 --/10 Why is it so important that we understand the concept of the PDF in a continuous probability distribution if we never use it to calculate the P(X= x)? 1 Because the PDF is used to determine the Z score 2 Because we use the CDF to calculate probabilities 3 Because we must keep in mind that our calculations will be wrong to some extent if the shape of our data distribution differs from the shape defined by the PDF of the model we are using 4 Because we could never remember the calculus involved in finding the area under a curve defined by the PDF 5 All of the choices above 6 None of the choices above Question 10 --/10 If the average time between events is 4 months and the event occurred today, what is the probability that is will take more than another 2 months for the next event to occur 1. .9997 2 .3935 3 .6065 4 .0003 5 All of the choices above 6 None of the choices above Question 9 -- / 10 If the minimum is 25, the mode is 35, and the maximum is 41, what is the P(X 1 1.0000 2 .9896 3 .9869 4 .9986 5 All of the choices above 6 None of the choices above Question 8 --/10 The value of the population mean when z is 1.22, the population standard deviation is 3, and x is 22 is 1 18.3400 2 13.8400 3 14.8300 4 18.4300 5 All of the choices above 6 None of the choices above Question 4 --/10 The Empirical Rule tells us that 1 Approximately 95% of the observed values of X are expected to lie within 3 standard deviations of the mean in a normal distribution 2 Approximately 68% of the observed values of X are expected to lie within 2 standard deviations of the mean in a normal distribution 3 Nearly all of the observed values of X are expected to lie within 3 standard deviations of the mean in a normal distribution 4 Approximately 99.73% of the observed values of X are expected to lie within 2 standard deviations of the mean in a normal distribution 5 All of the choices above 6 None of the choices above