Paul is comparing the cost of cell phone services. At CellCoA, the phone he wants costs $305 and the unlimited calling plan cost
s $45 per
month. At CellCoB, Paul can purchase the same phone for $350 and get an unlimited calling plan for $30 per month. In how many months
will both plans cost the same?
These equations, which are graphed below, represent the situation.
y = 45x + 305
y= 30x + 350
Here, x represents the
number of months and y represents the amount paid.
80
70
60
10)
month. At CellCoB, Paul can purchase the same phone for $350 and get an unlimited calling plan for $30 per month. In how many months
will both plans cost the same?
These equations, which are graphed below, represent the situation.
y = 45x + 305
y= 30x + 350
Here, x represents the
number of months and y represents the amount paid.
80
70
60
10)
1 answer:
You might be interested in
She worked 9 hours at baby-sitting and 6 hours at her parents store.
Step-by-step explanation:
Let,
Baby-sitting hours = x
Hours at parents store = y
Total hours = 15
Amount earned = $93
According to given statement;
x+y=15 Eqn 1
5x+8y=93 Eqn 2
Multiplying Eqn 1 by 5;
Subtracting Eqn 3 from Eqn 2;
Dividing both sides by 3;
Putting y=6 in Eqn 1
She worked 9 hours at baby-sitting and 6 hours at her parents store.
Keywords: linear equations, subtraction
Learn more about linear equations at:
#LearnwithBrainly
Answer:
They need to survey 4145 residents.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of .
The margin of error is given by:
99% confidence level
So , z is the value of Z that has a p-value of
, so
.
At least how many residents do they need to survey if they want to be at least 99% confident that the sample proportion is within 0.02 of the true proportion?
This is n for which . As we have no estimate for the proportion, we use
. So
Rounding up:
They need to survey 4145 residents.