b)

Given:

(i) growth rate = 1.57% / annum, y = estimated number of ppl in Mexico at a time x years after 2002. Write the formula relating x and y in form y=b(a^x)

So we had to write a formula including appropriate values for a and b in the formula.

I thought of using the compound interest formula A = P(1+r)^n, as it requires similar calculations and asks similar things, for eg. accumulation, or 'compounding' of years.

so I said : y = a ( 1 + b ) ^ x , where y = estimated number of ppl in Mexico at a time x years after 2002, a= initial population, b = growth rate, x = compounding periods.

but i wasn't sure if it should be y=P(1+r)^x

(ii) using formula y=a(1+b)^x,

y = 103 400 000 x (1 + 1.57/100 ) ^ 2

y = 106, 627, 247 (to nearest thousand)

I had a go at least! You get marks for having a go, even if you only lose one for getting the wrong result. Hope y ll can understand that!

Im outtie!