Answer:
Step-by-step explanation:
Any time you have compounding more than once a year (which is annually), unless we are talking about compounding continuously, you will use the formula

Here's what we have:
The amount after a certain time that she has in the bank is 4672.12; that's A(t).
The interest rate in decimal form is .18; that's r.
The number of times the interest compounds is 12; that's n
and the time that the money is invested is 3.5 years; that's t.
Filling all that into the formula:
Simplifying it down a bit:
Raise 1.015 to the 42nd power to get
4672.12 = P(1.868847115) and divide to get P alone:
P = 2500.00
She invested $2500.00 initially.
Answer:
Here's a possible example:
Step-by-step explanation:

Each piece is linear, so the pieces are continuous by themselves.
We need consider only the point at which the pieces meet (x = 3).

The left-hand limit does not equal ƒ(x), so there is a jump discontinuity at x =3.
Answer:
5.9x + 1.4
Step-by-step explanation:
5.5 + 2.1x + 3.8x - 4.1
= 5.9x + 1.4
Answer:
The proportion of piano prices higher than the electric piano is 98.3%
Step-by-step explanation:
The first thing to do here is to calculate the standard score of the price of the electric piano given.
Mathematically, this is
z-score = (x-mean)/SD
where mean is 3000 and SD is 200, x is 2576
z-score = (2576-3000)/200 = -2.12
Now we proceed to calculate the probability of this z-score
The probability we are trying to calculate is
P( x > $2576) or simply P ( z > -2.12)
Using standard score probability calculator or table, we have
P(x>2576) = 1 - P(x<2576)
But, P(x<2576) = 0.017003
P(x>2576) = 1 - P(x<2576) = 0.983
This is same as 98.3%
.15x = 75
Divide both sides by .15 you get 500 minutes