USING EXCEL
- For the most part,our multiple-choice quiz (and Evaluation) questions have fourpossible answers. (Yes, I know. I throw in an extra answer now andthen!) Suppose you come to a quiz hoping to guess yourway through to a decent grade. Find the probability of guessingat least 5 out of the 10 multiple-choice questionscorrectly, using BINOM.DIST with pdf (i.e., summing each of theindividual probabilities of 5, 6, ….., 9, 10), andthen with cdf (i.e., taking the complement of one of thecdf values.) Round (final answer only) to 3digits. Do not round your intermediateanswers.
Make sure you label your two methods,“Method 1” and “Method 2” so thatthey serve as headers for the work you display beneath each.
So would you consider this eventlikely or unlikely to occur? Explain your answer.
Review: usingBINOM.DIST(x, n, p, false) is the pdf function, since the falsetells you that this is the probability for only x successes out ofn trials with a probability, p, on any trial.
For example, if you’re interested incomputing P(X=10) for n = 20, p = .5, then enter
“BINOM.DIST(10,20,5, FALSE)”
However, if you wish to calculate theP(X ? 10), enter
“BINOM.DIST(10,20,.5,TRUE)”, since“TRUE” indicates that you wish Excel to give the cumulativeprobability, that is the sum of the following probabilities:
P(X=0)+P(X=1)+P(X=2)+P(X=3)+P(X=4)+…+P(X=10); whereas inserting
“FALSE” gives you only P(X=10).
- Now answer the samequestions in (a), assuming that each of our weekly quiz questionshas 5 answers instead of 4. Again, use both methods, making sure tolabel your work “Method 1” and “Method 2”.
