9/21/2010 HW.backwardsZ.CI.&KEY Page 1 hw.backwardsZ.CI.&KEY.docBackwards Z, CI Revised 09/20/10FOR ALL HOMEWORK.  IF MORE THAN ONE PAGE, THEY MUST BE STAPLED. OTHERWISE, NO CREDIT.  NO RIPPED-OUT EDGES OF PAPER – ALL EDGES MUST BE SMOOTH FOR CREDIT.  SHOW ALL WORK, INCLUDING FORMULAS WITHOUT NUMBERS, USING SYMBOLS.  TURN IN **BEFORE YOU SIT DOWN** EVEN IF I’M LECTURING. OTHERWISE NO CREDIT.  UPPER RIGHT CORNER MUST HAVE YOUR CLASS ID Suppose all the X_(using samples of size 25) from a population distribution could be collected into their own distribution, where they would be normally distributed with a mean of 20 and a variance of 16/25 which means X_∼N⎝⎜⎛⎠⎟⎞μ,σ2n. (It is therefore also true that X ∼N(μ,σ2) which is the population distribution.) #1. Looking at all possible X_s in this sampling distribution, about 96.99% of them will exceed some number y. Another way to state this is: P(X_> y) = 0.9699. Show work (including formulas without numbers) in computing the value of y. Draw the normal graph with both axes and label everything
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