math help plz for pure 30

In another city, the schools vary in size from 200 to 2 000 students. As a result, the

volleyball league is organized into three divisions. The first division is for schools with less than 500 students, the second division is for schools with 500 to 1 000 students, and the third division is for schools with more than 1 000 students.

The table below shows the populations of two schools from 1995 to 2004. School *A *has a population that declined from 1995 to 2004. School *B *has a population that grew from1995 to 2004.

http://i42.tinypic.com/2e3ps9i.jpg

**1. **Use exponential regression equations of the form *y *= *ab**t*, where *y *is the school

population and *t *is the number of years after 1995, to model the populations of

School *A *and School *B*. Express *a *to the nearest whole number and *b *to the

nearest thousandth.

**school A :**

**y = -0.030x + 3.167**

**log b = -0.030 ----> b = 10^(-0.030) = 0.933**

**log a = 3.167 ----> a = 10^3.167 = 1469**

**school B:**

**y = 0.015x + 2.682**

**log b = 0.015 ----> b = 10^(0.015) = 1.035**

**log a = 2.682 ----> a = 10^2.682 = 481**

**2. **Determine, to the nearest tenth of a percent, the average annual rate of increase or

decrease for each school.

**School A: ****1353(1 - r) ^9 = 755**

**(1 - r) ^9 = 755 / 1353 = 0.55802**

**1 - r = (0.55802) ^1/9 **

**r =- 6.2%**

**School B: 449(1 + r) ^9 = 646**

**(1 + r)^9 = 646/449 = 1.4388**

**1 + r = (1.4388)^1/9 = 1.0412**

**r = 4.2%**

**3. **Assuming the same annual rate of decrease, predict the population of School *A*

in September 2009. Show the mathematical basis for your prediction.

**4. **Assuming the same annual rate of increase and using the values of *a *and *b*

from the regression equation, predict the calendar year in which the population

of School *B *reaches 1 000 for the first time. Justify your prediction graphically

and algebraically.

**5. **Assuming the same annual rates of decrease and increase, predict the calendar

years in which Schools *A *and *B *play in the same division of the league. Justify

your prediction mathematically.

**6. **• Using the same set of axes, sketch the graphs of the regression equations for

the populations of School *A *and School *B *as a function of the years after 1995.

• Determine the point of intersection of the two graphs, and explain the

significance of the intersection point in the context of this project.

i did first two but struggling with rest of those. help me out here.

urgent project help please

well i am not relly gud at exp reg. i did first two but struggling with rest of those. help me out here plz. and could you plz tell me whther the first 2 are correct or not?

thanks in advance