multiple choice about funtion

[kris17]

Use the following for problems 6-9.
The value of U.S. trade with China from 1994 through 2004 can be approximated by
C(t)= 3t^2-7t+50 billion dollars where t is measured in years since 1994.

6) Find C(4):
a) 98
b) 56
c) 38
d) 50
e) None of the above.

7) Which of the following statements is the best interpretation of C(4)?
a) The value of U.S. trade with China in billions of dollars.
b) The value of U.S. trade with China in billions of dollars in 1994.
c) The value of U.S. trade with China in billions of dollars in 1998.
d)The amount that the value of U.S. trade with China was increasing per year in
1994.
e)The amount that the value of U.S. trade with China was increasing per year in
1998.

8) What is the average rate of change of the function between 1996 and 1998?
a)48
b)22
c)17
d)11
e)5

9) Which of the following statements is the best interpretation the answer to problem number 8?
a)The value of U.S. trade with China in billions of dollars.
b)The value of U.S. trade with China in billions of dollars in 1996.
c)The value of U.S. trade with China in billions of dollars in 1998.
d)The amount that the value of U.S. trade with China increased per year, on average, between 1996 and 1998.
e)The amount in billions of dollars that the value of U.S. trade with China increased per year, on average, between 1996 and 1998.



I got: E,C,D,A. Yes or no?

 

[Deleted member 4993]

Use the following for problems 6-9.
The value of U.S. trade with China from 1994 through 2004 can be approximated by
C(t)= 3t^2-7t+50 billion dollars where t is measured in years since 1994.

6) Find C(4):
a) 98
b) 56
c) 38
d) 50
e) None of the above.

7) Which of the following statements is the best interpretation of C(4)?
a) The value of U.S. trade with China in billions of dollars.
b) The value of U.S. trade with China in billions of dollars in 1994.
c) The value of U.S. trade with China in billions of dollars in 1998.
d)The amount that the value of U.S. trade with China was increasing per year in
1994.
e)The amount that the value of U.S. trade with China was increasing per year in
1998.

8) What is the average rate of change of the function between 1996 and 1998?
a)48
b)22
c)17
d)11
e)5

9) Which of the following statements is the best interpretation the answer to problem number 8?
a)The value of U.S. trade with China in billions of dollars.
b)The value of U.S. trade with China in billions of dollars in 1996.
c)The value of U.S. trade with China in billions of dollars in 1998.
d)The amount that the value of U.S. trade with China increased per year, on average, between 1996 and 1998.
e)The amount in billions of dollars that the value of U.S. trade with China increased per year, on average, between 1996 and 1998.



I got: E,C,D,A. Yes or no?

Show work - if you want to know why.

 

[kris17]

ok so when I plugged 4 in the function I got: C(t)=48-28+50which is 70. so none of the above. as for the second part about my interpration, thats just what i think



for 8) i plugged in 2 first so got 12-14+50 which is -48 then plugged iin 4 and got 48-28+50 which is 70 . subtract those and its 22. which is B. (looks like i messed up on that one the 1st time i did it)

 

[kris17]

can anyone help me with this one?

 

[Deleted member 4993]

ok so when I plugged 4 in the function I got: C(t)=48-28+50which is 70. so none of the above. as for the second part about my interpration, thats just what i think .... Correct



for 8) i plugged in 2 first so got 12-14+50 which is -48 then plugged iin 4 and got 48-28+50 which is 70 . subtract those and its 22.

22 is the total change - not the rate. (the question asks :"What is the average rate of change of...)

What do you have to do to find the rate?


which is B. (looks like i messed up on that one the 1st time i did it)

.

 

[kris17]

ohh right. the rate of chnage is found by:m = (y₂-y₁)/(x₂-x₁) so I plugged 2 in the equation first(because 1996-1994=2yrs), getting 48. so my first point is (2,48). Then I plugged in 4(1998-1994), getting 70. so my second point is (4,70). so for the rate of change i ended up with
22/2 which is 11. So it would be D.

for number 7, is it wrong? Im unsure about that one