Expert: Richard J. Raridon - 9/12/2008

Question
I have like 13 questions i need help with so here they go.

1. In 1991 the life expectancy of males in a certain country was 70.1 years.  In 1995 it was 72.6 years.  Let E representn the life expectancy in years and t represent the number of years since 1991.
a.The linear function E(2) that fits the data is
E(t)=___t + ___ (round to the nearest tenth).
b. Use the function to predict the life expectancy of males in 2007.  E(16)=____.

2. Write an equation of the line containing the given point and parallel to the given line.
(8,-2) 4x-9y=7  The equation of the line is y=____________.

3. The table lists data regarding the average salaries of several professional athletes in the years 1991 and 2001.
YEARS   AVERAGE SALARIES
1991     $272,000
2001     $1,370,000
Use the data points to find linear function that fits the data.  Then use function to predict the average salary in 2005 and 2010.  
a. Linear function that fits the data is
S(x)=________.
b. Predict the average salary for 2005 is $_______.
c. Predict the average salary for 2010 is $______.

4.  Graph the equation using the slope and the y intercept.    y=-8/3x-4.

5. Find the slope and the y intercept.  f(x)=-7x-9
a. The slope is _________
b. The y intercept is (0,__)

6.  Find the slope and the y intercept 10-1/5y=2x.
a. The slope is ____
b. The y intercept is _____

7.  Find the intercepts and the graph the equation.
3x + 5y =15

8.  Find the slope-intercept equation of the line that has the given charcteristic.   Slope 1.7 and the y intercept (0,-7)
the slope intercept equation is y=____________.

9.  the function p(d)=1+d/33 give the pressure, in atmosphere (atm), at the depth d in the sea (d is in feet) find the pressure at 150 feet.
The pressure at 150 feet is _____ atm.

10.  Given the function f described by f(x)=2x find following.
a. f(-9)
b. f(12)
c. f(28)

11.  Find the slope if it exists of the line containing the parallel points.
(-11.3, 19.1) and (-11.1, 18.9)  
The slope is m=_______________.

12.  Find the function value F(x) = x^3
f(-9)

13. Find an equation of the line having the given slope and containing the given point.  Express your answer in the form x=a, y=b, y=mx+b.
a. m=o, (0,-6)
The equation of the line is y=______________.
b. (-4,-4) and (5,5)
The equation of the line is y=______________.

Answer
1. E(t) = 70.1+0.625t, E(16) = 80.1
2. y = (4/9)x -50/9
3. S(x) = 272000+109800t where t = years since 1991
S(14) = $1,809,000, S(19) = $2,358,200
4. I can't graph it for you.  It only takes two points to graph a straight line.  Just put in a value for x, calculate y and plot (x,y). Repeat for another value of x.  Connect the points.
5. a. -7, b. -9
6. a. -10, b. 50
7. x-int = 5, y-int = 3 draw line between them
8. y = 1.7x -7
9. 5.55
10. a. f(-9) = -18, you can the others
11. two points can't be parallel, slope = -1
12. f(-9) = (-9)^3 =
13. a. y = -6 b. y=x