Probability when z-score is negative

1. How do you find probability with negative z-score?
2. What happens if z-score is negative?
3. How do you find the p value of a negative z-score?
4. Can a probability score be negative?

How do you find probability with negative z-score?

If you have a negative z-score simply use the same table but disregard the negative sign, then subtract the area from the table from 1.

What happens if z-score is negative?

A positive z-score says the data point is above average. A negative z-score says the data point is below average. A z-score close to 0 says the data point is close to average. A data point can be considered unusual if its z-score is above 3 or below −3 .

How do you find the p value of a negative z-score?

Find the area for the negative z-value and double it to obtain the p-value. For our example, the area less than z = -2.5 equals the region greater than z = 2.5, thanks to the symmetry. In this case, the z-table indicates that the area less than z = -2.5 is 0.00621.

Can a probability score be negative?

Finding z-scores from probabilities

Finally, decide if the z-score should be positive or negative, based on whether it was on the left side or the right side of the mean. Remember, z-scores can be negative, but areas or probabilities cannot be.