Answer:
275
Step-by-step explanation:
550 divided by 2 is 275.
This question out to be one that we could all answer almost instantly. If the area under the std. norm. curve to the left of z is 0.5 (exactly half of that area), the z value is zero (0).
Let the equation representing the function be y = -mx + c; where m is the charge per minute and c is a initial balance.
25.04 = -31m + c . . . . . (1)
19.74 = -64m + c . . . . . (2)
(1) - (2) gives: 5.3 = 33m
m = 5.3/33 = 0.16 (i.e. charge per minute is 16 cents)
From (1), 25.04 = -31(0.16) + c
25.04 = -4.96 + c
c = 25.04 + 4.96 = 30 (i.e. initial balance is $30)
Remaining credit after 85 minutes call is -85(0.16) + 30 = -13.6 + 30 = $16.40
Answer:
A.\ \ r(d)=-100(d-25)^2+122,500
Hope this helps!
Well from what I could remember from this lesson from school I think it would be 85 because you either subtract or divide...