The median of the results was 80 points out of 100, with a standard deviation of 6 points. which of the following numbers is closest to the number of students that got more than 86 but less than 92 points?
1
3
7
9

Z-score is a statistical tool that is used to estimate the probability of finding a number in a normal distribution of data. A normal distribution is described as a function in which the mean is zero, the standard deviation is 1 and that the area under the curve is equal to 1. 

The z-score at 86 is z = (86-80)/6 = 1. the probability to the right is 0.1587. 
The z-score at 92 is z = (92-80)/6 = 2. the probability to the left is 0.9772. 
The difference in probability is equal to 0.8185. We multiply this to the number of total students to get the answer. 

The answer is biodiversity resulting from new ancestors.