Answer:
The costs of the plan are $0.15 per minute and a monthly fee of $39
Step-by-step explanation:
Let
x ----> the number of minutes used
y ----> is the total cost
step 1
Find the slope of the linear equation
The formula to calculate the slope between two points is equal to

we have the ordered pairs
(100,54) and (660, 138)
substitute


step 2
Find the equation of the line in point slope form

we have

substitute

step 3
Convert to slope intercept form
Isolate the variable y

therefore
The costs of the plan are $0.15 per minute and a monthly fee of $39
................................
Step-by-step explanation:
You can use PEMDAS to solve this problem from left to right.
First, do 15 ÷ 3 to get 5.
Next, do 2 x 10 to get 20.
Lastly, add 5 and 20 to get 25.
<u>15 ÷ 3</u> + 2 x 10
5 + <u>2 x 10</u>
<u>5 + 20</u>
25
Answer:
0.9792
Step-by-step explanation:
Data provided in the question:
Average gross sales = $1,240
Standard deviation = $180
sample size = 40
Now,
standard deviation of sample average
=
=
= 28.46
Now,
z value for 1200 =
= -1.4,
and,
p value for (z = -1.4) = 0.0808
therefore,
P(average < $1200) = 0.0808
Thus,
probability that the average over the next 40 weekdays will exceed $1,200
= 1 - 0.808
= 0.9792