Please Help...Normal Distribution Probabilities


TS Contributor
You're given that the distribution is normal with a mean of 3 and std dev of 4. To find the probability that x >= 2.5, convert x into a z-score:

z = (x - mean) / std dev

z = (2.5 - 3) / 4

Once you compute z, use the normal distribution tables to find the proportion of the area under the normal curve above the computed z score.