Talk:Standard normal table

Table

Why is this page referencing a specific type of table? The textbook I have in my class (not saying that it is the only answer) uses a different table, with prob's from 0.0000 to 0.4990. The Z values are the same, from 0.00 to 3.00. Shouldn't we reference all types, and provide methods and rationales for each? Andrew 19:07, 1 November 2007 (UTC)

I am fixing this, providing examples of at least two types of tables. Stephen Charles Thompson (talk) 06:14, 5 May 2012 (UTC)

Equation

I think the equation is $P(z)={\frac {1}{1+e^{-\Phi z}}}\!$ , but I can't find a source. Dude1818 (talk) 03:06, 16 April 2010 (UTC)

How to calc Z table

Cumulative from mean (0 to Z)

From Mathematica (yes I know, this is not a good source). Using erf() which is the Error Function

(* Normal distribution with mean of 0 and standard deaviation of 1 *)
cdf[x_] = CDF[NormalDistribution[0, 1], x]
1/2 (1 + Erf[x/Sqrt[2]])

N[cdf[1] - 1/2]
0.341345

N[cdf[2] - 1/2]
0.47725

N[cdf[3] - 1/2]
0.49865

110.22.20.252 (talk) 03:05, 3 April 2017 (UTC)

Expand Table, please

You go to the bother of creating a page with this important table ... and then stop it at z=3 ???? Wrong. What, are you worried about the cost of ink?

Expand the table, or I'll delete it.Jamesdowallen (talk) 14:17, 1 September 2016 (UTC)

Inserting the negative end of the cumulative z-score table

I'm going to be w:BOLD and do it because I need and so do many students. I calculated it all using the "Cumulative from mean (0 to Z)" table already on the page. Thecurran (talk) 11:51, 23 March 2020 (UTC)