If a large number of people guess randomly on each of 100 items on a true-false test, the mean would be expected to be ì=___*, and ó=__*.


What % of the examinees would be expected to get a score of 65 or >?

1 answer

The mean is p*N = 50
where p is the probability of getting gthe correct answqer by guessing at random. N is the number of tosses

The variance is p(1 -p)N = 25

The standard deviation is
ó = sqrt25 = 5.

Use a normal ditributuion curve for the probability of getting a score of 65 or better. You are talking 3 sigma from the mean.
Similar Questions
  1. TRUE OR FALSEThe burning of fossil fuels cause the earth to get warmer by putting carbon dioxide in the atmosphere and the
    1. answers icon 2 answers
    1. answers icon 1 answer
  2. Excerpts from Walt Whitman’s Song of MyselfNumber 33 Space and Time! now I see it is true, what I guess'd at, What I guess'd
    1. answers icon 9 answers
  3. True Equations Quick Check5 of 5 5 of 5 Items Question Priscilla has a number riddle for her friends. She wants them to guess
    1. answers icon 1 answer
more similar questions