Comments on: P(Z>1.96)? given Z has the sn dist(Z~N(0, 1)). HELP!!!! http://www.jambo.net/2007/01/25/pz196-given-z-has-the-sn-distzn0-1-help/ Wireless Hello - Meet People Nearby Fri, 21 Nov 2008 13:04:20 +0000 http://wordpress.org/?v=2.5.1 By: valier http://www.jambo.net/2007/01/25/pz196-given-z-has-the-sn-distzn0-1-help/#comment-682 valier Fri, 26 Jan 2007 07:18:40 +0000 http://www.jambo.net/blog/?p=181#comment-682 P ( 0 < Z < 1 ) = .34 P ( -1 < Z < 1 ) = .68 P ( -2 < Z < 2 ) = .954 P ( -1.96 < Z < 1.96 ) = .95 P ( -3 < Z < 3 ) = .9974 so... P ( Z > 1.96 ) = 1-.95 = .05/2 = .025 z is everything greater than 1.96, or 2 stdev away from the mean (0)… so take the total (which is always 1) minus 95% and then divide that in half since we're only talking about half of the "graph." and then… P ( Z > -1.96 ) = .95 + .025 = .975 P ( 0 < Z < 1.96 ) = .95/2 = .475 P ( -1 < Z < 1.96 ) = .95/2 + .68/2 = .475 + .34 = .815 enjoy! P ( 0 < Z < 1 ) = .34

P ( -1 < Z < 1 ) = .68

P ( -2 < Z < 2 ) = .954

P ( -1.96 < Z < 1.96 ) = .95

P ( -3 < Z < 3 ) = .9974

so...

P ( Z > 1.96 ) = 1-.95 = .05/2 = .025
z is everything greater than 1.96, or 2 stdev away from the mean (0)… so take the total (which is always 1) minus 95% and then divide that in half since we’re only talking about half of the “graph.”

and then…
P ( Z > -1.96 ) = .95 + .025 = .975

P ( 0 < Z < 1.96 ) = .95/2 = .475

P ( -1 < Z < 1.96 ) = .95/2 + .68/2 = .475 + .34 = .815

enjoy!

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