Next, find and record the value associated with z=2.31.8849 Remember that value represents the percentage of values below 1.2. First find z=1.2 on the z-score probability reference above.To evaluate the probability of a value occurring within a given range, you need to find the probability of both the upper and lower values in the range, and subtract to find the difference. What is the probability associated with a z-score between 1.2 and 2.31? Since the proliferation of the Internet, however, you can also use a free online calculator. Historically, it has been very common to use a z-score probability table like the one below to look up the probability associated with a given z-score: Z In this lesson, which is an extension of Z-scores and Z-scores II, we will practice both methods. To calculate the probability of getting a value with a z-score between two other z-scores, you can either use a reference table to look up the value for both scores and subtract them to find the difference, or you can use technology.
