What is a Normal Distribution?


We can say ”Normal distribution is a continuous distribution that is “bell-shaped”. Data are often assumed to be normal. Normal distributions can estimate probabilities over a continuous interval of data values.


Which Data Values Are Most Likely to be Observed in a Normal Distribution?

In a normal distribution, data are most likely to be at the mean. Data are less likely to farther away from the mean. Are the people around more likely to be short, tall, or average in height?

What is a Standard Normal Distribution?

Also we can say A standard normal distribution is a normal distribution with a mean=0 and standard deviation = 1.

standard normal

“All normal distributions can be converted into a standard normal distribution”

Why Convert to a Standard Normal Distribution?

The values for points in a standard normal distribution are z-scores. We can use a standard normal table to find the probability of getting at or below a z-score. (a percentile).

How do You Convert a Normal Distribution to a Standard Normal Distribution?

1. Subtract the mean from each observation in your normal distribution, the new mean=0.

2. Divide each observation by the standard deviation, the new standard deviation=1.