Wednesday, April 16, 2008

HI! This is COwMIlk How you guys prepare for the test about statistic tomorrow?? I think the important thing in this chapter is normal distribution .Follow with this is some formula :
+ Shapenorm(Low Value ,Hi value,mean, but I think you guys should change to Z-score ^^ because that easier (I think) there's how to use shapenorm: shapenorm(Low Z-score,Hi-Z-score).
+ InvNorm(Percent) this one is easy to use ,when you have the percent ,just use this formula and u will get the Z-score,remember this percent must be from the minimum point at left of the bell Shape to right of the bell Shape .
+ And everyone must know how to calculate Z-SCORE

Binomial Distribution
When binomial distribution approached to the normal distribution (np AND nq >= 5) we can use the formula of normal distribution.
+ binomialPDF(trial,percent,x) :
Ex: flip the coint 20 times
Trial --> we have 20 letters (H or T) --> trial is 20
percent--> 1/2--> trial is 1/2
The calculator will create 20 letters ( H or T)
X(optional of this formula) :if you don't put x , the calculator will show all of your results. (all the percent .If u put x = 5,the calculator only show 1 result ,that is the percent of exactly 5 letters in 20 letters.

+ binomialCDF(trial,percent,x) : the same with formula above, but it's have a LITTLE difference :P . When we put x=5 , the calculator will add all the percent from TTT(all of T)...or (All of H) to 5 letters H in 15 letters T (or 5 letters T in 15 letters H)

That's some things i think importance ...and ...that it ^^ ...GOODLUCK

MR.K when we hand in 4 questions ?????????

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