Answer:
the radius=9m2
i solve the question and answer is 9
Approximately 68% of a normal distribution lies within one standard deviation of the mean, so this corresponds to students with scores between
.
The y-intercept is 7500 and it represents when the account is still active or have been inactive for 0 years.
You can set it up like:
400/2.5 = 600/x; now cross multiply
400x = 2.5(600)
400x = 1,500; now divide both sides by 400 to isolate the x, and you get x = 3.75 hours