18. According to an IRS study, it takes an average of 330 minutes for taxpayers to prepare, copy, and electronically file a 1040 tax form. A consumer watchdog agency selects a random sample of 40 taxpayers and finds the standard deviation of the time to prepare, copy, and electronically file form 1040 is 80 minutes.

a. What assumption or assumptions do you need to make about the shape of the population?
b. What is the standard error of the mean in this example?
c. What is the likelihood the sample mean is greater than 320 minutes?
d. What is the likelihood the sample mean is between 320 and 350 minutes?
e. What is the likelihood the sample mean is greater than 350 minutes?

... If one degree is selected at random, find the following probabilities. Probability of any event i = Number of occurrences of event i / Total number of events a ...

... According to the fundamentals of probability, P(event) must be between ____ and _____, and the probabilities of all events in an experiment must sum to ____. ...

... 6) The coin being tossed and the die being tossed are independent events so their probabilities will be multiplied together. Probability of getting heads 1/2. ...

... trials, but with unequal Probabilities of success from trial to trial. Assume n = 2 independent trials are to be performed; the probability of success for the ...

... 12. Given the following probability distribution, determine the given probabilities: x P(x) 0 0.10 1 0.20 2 0.55 3 0.15. a). P(x < 1) = b). P(1 < x < 3) =. ...

... right column contains relative frequencies, which may be thought of as probabilities. Therefore, we may view the table as describing a probability distribution ...

Probability Distribution Questions: Normal, Poisson using Excel worksheet functions. ... Reject region Lower limit 19.8 Upper limit 20.3. Probability of reject. ...