The current rate is simply equal to $175 per month, let
us call this as rate A:
A = 175
The new rate is $94 plus $4.50 per devices, let us call
this as rate B:
B = 94 + 4.50 x
where x is the number of devices connected to the network
The inequality equation for us to find x which the new
plan is less than current plan is:
94 + 4.50 x < 175
Solving for x:
4.50 x < 81
x < 18
So the number of devices must be less than 18.
- From the graph, we can actually see that the new rate
intersects the current rate at number of devices equal to 18. So it should
really be below 18 devices.
The last selection should be your answer
Let the number of nickels found be n, the number of dimes be d and the number of quarters be q.
i) "you have twice as many quarters as dimes and 42 coins in all."
means that 2d=q, and n+d+q=42
we can reduce the number of unknowns by substituting q with 2d:
n+d+q=42
n+d+2d=42
n+3d=42
We can write all n, d and q in terms of d as follows:
there are n=42-3d nickels, d dimes and q=2d quarters.
ii) In total there are $6.60 dollars,
1 nickel = 5 cent = $0.05
1 dime = 10 cent = $0.1
1 quarter = 25 cent = $0.25
thus
(42-3d)*0.05 + d*0.1 +2d*0.25= $6.60
2.1 - 0.15d+0.1d+0.5d=6.60
2.1+0.45d=6.6
0.45d=6.6-2.1=4.5
d=4.5/0.45=10
iii)
so, there are 10 dimes, 2d=2*10=20 quarters and 42-3d=42-3*10=12 nickels.
Answer: 10 dimes, 20 quarters, 12 nickels
Answer:
See below
Step-by-step explanation:
a) <u>Using the first two lines to get the equation:</u>
Since t = 0 represents a start point, the y-intercept is 163488
<u>Slope is:</u>
- (168392 - 163488)/10 = 490.4
<u>And the equation:</u>
- P(t) = 490.4(t - 1970) + 163488
b) Prediction of the population in 2012 using the function:
- P(2012) = 490.4(2012 - 1970) + 163488 = 184084.8
As we see the number we got is less than the one on the line 3 of the table. So the model underestimated the actual population.
