Middle on the Normal distribution

Z = =.1003 What is going on here? It is just an exercise in using the Z table and finding the middle.8000, or middle 80% of values. Note, with the middle.8000,.2000 is left and half is on each side. From a practical point of view, from the table has.1003 in the low tail. This is more than the.1000, but is the closest in the table. Z = 1.28 means we would have.1003 in the upper tail. Thus between Z’s and 1.28 we have the middle.8000.

Z What is going on here? It is just an exercise in using the Z table and finding the middle.9000, or middle 90% of values. Note, with the middle.9000,.1000 is left and half is on each side. From a practical point of view, from the table has.0500 in the low tail. The tradition here is to go in the middle of and Z = means we would have.0500 in the upper tail. Thus between Z’s and we have the middle = =.0500

Z = =.0250 What is going on here? It is just an exercise in using the Z table and finding the middle.9500, or middle 95% of values. Note, with the middle.9500,.0500 is left and half is on each side. From the table has.0250 in the low tail. Z = 1.96 means we would have.0250 in the upper tail. Thus between Z’s and 1.96 we have the middle.9500.

Problem 18 page 219 π =.77 and thus the standard error = sqrt((.77)(.23)/200)) =.03 when rounding. a. The Z for.75 is ( )/.03 = -.67 and the Z for.80 is ( )/.03 = Thus we have =.5899 b. Remember the middle uses Z’s of and Thus the lower sample percentage is found by solving for p in the formula (really just the Z score formula applied to proportions) = (p -.77)/.03 or p = (.03) +.77 = and on the high end = (p -.77)/.03 or p = 1.645(.03) +.77 = c. The Z’s here are and 1.96 so we get.77 + and So on the low side we have.7112 and on the high side we have.8288