Suppose a fair die is rolled 1000 times. Estimate the probability that the number of 6s is between 150 and 180.
I know the expected value is 167, and to get the probability over a range you use that (X-Ex(X))/StDev and use that to obtain the Z-score, subtract, etc. - but what do you use for standard deviation for this problem? I thought it was np(1-p) but that gives me a far higher value than I thought it should.
2006-09-15 17:03:29 · 3 answers · asked by Anonymous 3 in Science & Mathematics ➔ Mathematics
the standard deviation is sqrt(np(1-p))
p([149.5-166.7/11.785]
p(-1.44
please check for errors.
2006-09-15 18:54:23 · answer #1 · answered by Anonymous · 0⤊ 0⤋
6
2006-09-16 00:04:36 · answer #2 · answered by Anonymous · 0⤊ 0⤋
If you say of basic probability, no matter how many times you rolls, you always have one sixth the chance that the number is 6, unless train to roll it other wise, which the trickster did.
2006-09-16 01:19:22 · answer #3 · answered by cybtrker 3 · 0⤊ 1⤋