Mgq 301

EXCEL FORMULA SHEET DISTRIBTIONS Binomial Distributions

For an EXACT probability =BINOMDIST(x,n,p,false) For less than or equal to x (at most x) =BINOMDIST(x, n, p, true) For less than x =BINOMDIST((x-1), n, p, true) For greater than x =1-BINOMDIST(x, n, p, true) For greater than or equal to x (at least x) =1-BINOMDIST((x-1), n, p, true)

Normal Distributions

To find the probability of a z-score (instead of using the Standard Normal Table!!) =NORMSDIST(z) * (used for P(z < ?)) =1-NORMSDIST(z) *(used for P(z > ?)) =NORMSDIST(z1) – NORMSDIST(z2) *(used for “between” probabilities) For an EXACT probability

*You will not be given “exact” probabilities because these are continuous distributions and exact values cannot be measured.

For probability less than or equal to x (at most x) =NORMDIST(x, mean, stddev, true) For probability less than x *same as above since Normal Distributions are continuous! For probability greater than x =1-NORMDIST(x,mean, stddev, true) For probability greater than or equal to x (at least x) *same as above since Normal Distributions are continuous! Given the percentile (probability) with objective to find the data value (x-value) =NORMINV(percentile, mean, stddev) If SAMPLING….with intent to determine the probability of the AVERAGE (mean) of the SAMPLE =NORMDIST(sample MEAN, population MEAN, STDERROR, true) *where STDERROR of the MEAN is:

**IF given a FINITE population and n/N > 5% apply the “Finite Correction Factor”

IF computing the STDERROR of a PROPORTION instead of the Mean: Compute the Z-score and use =NORMSDIST(z)

(π = Population %, p = sample %)