Kori is analyzing a normal data distribution, but the data provided is incomplete. kori knows that the mean of the data is 120 and that 84% of the data values are less than 130. find the standard deviation for this data set.

SD = 10.1

Step-by-step explanation:

We have been given that Kori knows that the mean of the data is 120 and that 84% of the data values are less than 130.

We will use z-score formula to find standard deviation of our given data set.

, where,

= z-score,

= Random sample score,

= Mean,

= Standard deviation.

Let us find z-score corresponding to the area of population under curve less than 84%.

From normal distribution table we get that z-score corresponding to area less than 84% is 0.99.    

Upon substituting our given values in z-score formula we will get,

Therefore, the standard deviation of our given data set is 10.1.