Why is Z0.05 = 1.645?


Super Moderator
I'm using a standard normal table from back of my text, and I can't find 1.645 anywhere. If anything, shouldn't it be 0.4801? What am I missing? Please see the table I'm using for reference.. thank you

You’re reading the table incorrectly. The value of p=0.4801 is the proportion of under the standard normal distribution that is to the right of a Z-score of 0.05.

Use (only) the first column on the left to obtain a Z-score…i.e. go down this column and look for 1.6 – then move to right to find the second decimal place 1.64 and subsequently obtain the proportion of the curve to right of this value which is approximatley 0.05