Enter the absolute value of the z-score and the standard normal cumulative distribution function into the calculator to determine the Level of Significance (p-value). This calculator can also evaluate any of the variables given the others are known.

Level Of Significance Formula

The following formula is used to calculate the Level of Significance (p-value) in a hypothesis test. 

p-value = 1 - Z(ABS(z))

Variables:

  • p-value is the Level of Significance
  • Z is the standard normal cumulative distribution function
  • z is the z-score (standard deviation)

To calculate the Level of Significance, first calculate the absolute value of the z-score. Then, find the corresponding value in the standard normal cumulative distribution function. Subtract this value from 1 to get the p-value.

What is a Level Of Significance?

A level of significance is a statistical term that represents the probability of rejecting a null hypothesis when it is true. It is often denoted by the Greek letter alpha (α) and is used to determine the threshold for rejecting the null hypothesis. The level of significance is typically set at 0.05, which means there is a 5% risk of concluding that a difference exists when there is no actual difference. Lowering the level of significance reduces the chances of making a Type I error (false positive), but increases the chances of making a Type II error (false negative).

How to Calculate Level Of Significance?

The following steps outline how to calculate the Level of Significance using the formula: p-value = 1 – Z(ABS(z)).

  1. First, determine the value of Z, which represents the standard normal cumulative distribution function.
  2. Next, determine the value of z, which represents the z-score (standard deviation).
  3. Next, calculate ABS(z), which represents the absolute value of the z-score.
  4. Then, substitute the value of ABS(z) into the formula p-value = 1 – Z(ABS(z)).
  5. Finally, calculate the Level of Significance (p-value) using the formula.
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

p-value (Level of Significance) = 0.05

Z (standard normal cumulative distribution function) = 1.96

z (z-score) = 1.5