Answer:
18
Step-by-step explanation:
We have been given that the standard deviation of a group of 20 scores is 15 and we are asked to find variance.
Since we know variance is square of standard deviation. In order to find out the variance of the given data we have to take the square of 15.

Therefore, our variance is 225.
• Use slope to graph linear equations in two variables.
• Find the slope of a line given two points on the line.
• Write linear equations in two variables.
• Use slope to identify parallel and perpendicular lines.
• Use slope and linear equations in two variables to model and solve real-life problems.
2
no these lines are perpendicular