James C. answered • 09/17/19
Doctoral Candidate (and a Master's) in Statistics With Nine Years Exp.
Hi Aaron, it is helpful to provide as much information as possible when asking this type of question. For instance, are you conducting a one- or two-tailed test? And if that is not a part of the question, does it specify a probability, or alpha level?
The probability of finding a value of z > 1.26 from a standard normal distribution (µ = 0, σ = 1) depends primarily on your probability (or alpha) level (e.g., .01, .025, .05, .10, etc.).
You'll note that on the z-table (typically in the appendix of your statistics textbook), includeds a z-table, with z-scores along the left-hand size and probability values on top from left to right. That is, the z-table has the z-scores on the y-axis and the alpha level on the x-axis (at the top of the table).
For the typical alpha level of .05, z > 1.26 = 0.8961653.
However, keep in mind that your statistics question likely includes a specific alpha level, which may NOT be .05. Therefore, you will need to use the z-table to look up the value for yourself.
I hope this helps!
James
