anonymous 5 years ago I need help with exponential regression...I have E(x)=164.96(1.03)^x for equation for high school graduates...need to find the first year of the decade in which number of graduates will reach 5 million

1. anonymous

E a function of x, E is what and x is what? im guessing E is graduates and x is year?

2. anonymous

yes I used cal to get a b and r

3. anonymous

plug 5mill into E(x) and solve for x

4. anonymous

yes got that but do I ln or log...can't remember

5. anonymous

years are in decades and graduates are in 1000s so would I divide 5 mil by 100

6. anonymous

do log base 1.03 there is probably a key on your calculator

7. anonymous

is that ln

8. anonymous

actually im sorry you are right take the natural log of both sides. and the exponent of x will come out as a multiple of ln(1.03) so $\ln(1.03^x) = xln(1.03)$ ln(1.03) is just a constant so you can divide by it on both sides

9. anonymous

thank you for the confirmation

10. anonymous

yeahp

11. anonymous

one more thing I have year 2050 from the linear function and year 2070 from the exponential...which one seems more reasonable?

12. anonymous

based on the values of correlation factor r the linear function would be but if you're looking at 5 million wouldn't it take less years to get there Exponentially versus linearly

13. anonymous

im not sure from what was given i only know of E(x) and x,

14. anonymous

L(x)=33.79x-135.77

15. anonymous

used 5000 instead of 5 mil bc grads in 1000s is that right?

16. anonymous

yeah

17. anonymous

yeah to which question, lol?

18. anonymous

lol just agreeing with the thing you said about linear versus exponential growth it would have to be 2050. but i would look into that more as to how to get to that answer

19. anonymous

ok thanks!