6 + (-3) would be the same as just saying 6-3 which would be equal to positive 3
Find the z-scores for the two scores in the given interval.

For the score x =391,

.
For the score x = 486,

Now you want the area (proportion of data) under the normal distribution from z = -1 to z = 0. The Empirical Rule says that 68% of the data falls between z = -1 to z = 1. But the curve is symmetrical around the vertical axis at z = 0, so the answer you want is HALF of 68%.
The equation for this problem is “y = x + 3”.
Answer:
1500÷3=m
Step-by-step explanation:
you have to divide 1500 by 3 to get the equal amount of minutes each person could use each month