Standard Normal Probabilities Table Question

Question

When using a Standard Normal Probabilities Table, how do you know which number to choose from the top row (0.0, 0.1, 0.2, etc.)

Answer 1

If you are deciding which column to use, then it seems you are looking to find a value from the table representing the area under the function (Std Norm Prob Curve).

The numbers at the top row represent the hundredths place in the Z value you are looking up.

Using the SNP table one can (generally) look up the area under the curve for a Z score between -2.99 and 2.99

The whole number and first decimal of the number are what the numbers on the left of the table represent.

The second decimal (hundredths place) is represented by the numbers on the top of the table. (this would be the 6th column)

If you were looking for the area representing a Z value of -1.00 then the hundredths value would be 0 and you would use the first column (0 column)

So, if you are looking for the area under the curve for a Z value of 2.45 the 5 hundredths (.05) character is the value you look up at the top of the table.