Answer: $19.6
Step-by-step explanation:
Linear function: f(x)=mx+c
, where m= rate of change in f(x) with respect to x.
c = Initial value.
Let c = Initial value of card , m= Charge per minute
x= Number of minutes calling time.
Then, 25.06= 38m+c (i)
21.03=69m+c (ii)
Eliminate (ii) from (i)

Put m in (i) , we get

i.e. f(x)=-0.13x+30
if x=80 then
f(80)= -0.13(80)+30
=-10.4+30
=19.6
Hence, the remaining credit after 80 minutes of calls = $19.6
Answer:
The dimensions of the can that will minimize the cost are a Radius of 3.17cm and a Height of 12.67cm.
Step-by-step explanation:
Volume of the Cylinder=400 cm³
Volume of a Cylinder=πr²h
Therefore: πr²h=400

Total Surface Area of a Cylinder=2πr²+2πrh
Cost of the materials for the Top and Bottom=0.06 cents per square centimeter
Cost of the materials for the sides=0.03 cents per square centimeter
Cost of the Cylinder=0.06(2πr²)+0.03(2πrh)
C=0.12πr²+0.06πrh
Recall: 
Therefore:



The minimum cost occurs when the derivative of the Cost =0.






r=3.17 cm
Recall that:


h=12.67cm
The dimensions of the can that will minimize the cost are a Radius of 3.17cm and a Height of 12.67cm.
Answer:98
Step-by-step explanation:
has to be higher then 97 so it has to be 98
Answer: x-bar = y-bar = 0 whereas z-bar = 8/3
M= (c^2)/8 which is intern equal to 2
Step-by-step explanation:
Find the area, by setting the limits as
= 



Therefore;
Mxy= 
z-bar = 8/3
M= 8
dividing it into two volume gives us = 4
means 

c=2