Table A & Its Applications - The entry in Table A - Table A’s entry is an area underneath the curve, to the left of z Table A’s entry is a proportion of the whole area, to the left of z Table’s entry is a probability, corresponding to the z-score value Math formula: P(z ≤ z 0 ) = 0.XXXX 2/1/2013Dr Anzhi Li 1

Problem Type I If z ≈ N(0, 1)P(z ≤ z 0 ) = ? Checking Table A, based on z 0 to find out the proportion P For type I problem, using table A to get the answer directly For example P(z ≤ ) = /1/2013Dr Anzhi Li 2

Problem Type II If z ≈ N(0, 1)P(z ≥ z 0 ) = ? The type II’s problem, use the following operation: P(z ≥ z 0 ) = 1 - P(z ≤ z 0 ) For example, P(z ≥ -0.71) = ? P(z ≥ -0.71) = 1 - P(z ≤ ) = = /1/2013Dr Anzhi Li 3

Problem Type III If z ≈ N(0, 1)P (z 2 ≤ z ≤ z 1 ) = ? In Table A, Look up z 1 → P 1 In Table A, Look up z 2 → P 2 Then we have: P (z 2 ≤ z ≤ z 1 ) =P 1 - P 2 For example, P (-1.4 ≤ z ≤ 1.3 ) = ? Look up z=1.3, P 1 = Look up z=-1.4, P 2 = P (-1.4 ≤ z ≤ 1.3 ) = – = /1/2013Dr Anzhi Li 4

Problem Type II 2/1/2013Dr Anzhi Li (height values) (z-score) _______________________I_______________________

Steps Summary Write down the Normal distribution N(µ, σ) for observation data set Locate the specific observation value X 0 or X 1 & X 2 Transfer x 0 to z 0 by z-score formula Check Table A using z 0 to locate the table entry P(z ≤ z 0 ) If is type I problem, the result is P(z ≤ z 0 ) If is type II problem, the result is: P(z ≥ z 0 ) = 1- P(z ≤ z 0 ) If is type III problem, the result is: P (z 2 ≤ z ≤ z 1 ) = P 1 - P 2 P 1 = P(z ≤ z 1 ), P 2 = P(z ≤ z 2 ) 2/1/2013Dr Anzhi Li 6