## How do you find probability using standard normal distribution?

Find P(a < Z < b). The probability that a standard normal random variables lies between two values is also easy to find. The P(a < Z < b) = P(Z < b) – P(Z < a). For example, suppose we want to know the probability that a z-score will be greater than -1.40 and less than -1.20.

**What is the probability of normal distribution?**

The normal distribution is a probability distribution, so the total area under the curve is always 1 or 100%. The formula for the normal probability density function looks fairly complicated. But to use it, you only need to know the population mean and standard deviation.

**How do you find the probability using the standard normal curve step by step?**

Use the standard normal distribution to find probability

- Go down to the row with the first two digits of your z-score.
- Go across to the column with the same third digit as your z-score.
- Find the value at the intersection of the row and column from the previous steps.

### How do you find probability with average and standard deviation?

Conclusion. In a normally distributed data set, you can find the probability of a particular event as long as you have the mean and standard deviation. With these, you can calculate the z-score using the formula z = (x – μ (mean)) / σ (standard deviation).

**How do you find probability with standard deviation?**

To calculate the standard deviation (σ) of a probability distribution, find each deviation from its expected value, square it, multiply it by its probability, add the products, and take the square root.

**How do you calculate probability distribution?**

How to find the mean of the probability distribution: Steps

- Step 1: Convert all the percentages to decimal probabilities. For example:
- Step 2: Construct a probability distribution table.
- Step 3: Multiply the values in each column.
- Step 4: Add the results from step 3 together.