## anonymous one year ago Whats the regression equation??? Height: 115, 124, 75, 75, 130, 74, 98, 87 Interval after min: 84, 78, 65, 69, 81, 72, 65, 66 Current eruption has a height of 92ft Use the significance level of 0.05. ŷ = ( ) + ( )x

1. amistre64

looks like a prime candidate for the ti83

2. amistre64

but then im not sure what the last line means for this

3. amistre64

input your values into list 1 and list 2 there is a function on your ti83 that will then give you the regression line.

4. amistre64

otherwise, it gets complicated, but excel or some spreadsheet makes life simpler for us

5. anonymous

ok I am trying now

6. anonymous

I cant get it

7. anonymous

This is my last question that I am having issues with

8. amistre64

yeah, its a bit complicated, but listing them is the key .... by hand, we would need to know more complicated results sum of x^2 sum of y^2 sum of xy sum of x sum of y average x average y and number of ordered pairs.

9. anonymous

I tried but I am getting the wrong data input

10. anonymous

11. amistre64

ive got a spread sheet worked out hold on

12. anonymous

Thank you so much!!!

13. amistre64

ok, this is what im getting, and ill explain it

14. anonymous

Okay thank you bc that looks confusing lol

15. amistre64

we want to utilize the point slope formula, our point (avgX, avgY) and a slope that is determined by the formula: $m=\frac{n\sum xy-\sum x\sum y}{n\sum xx-\sum x\sum x}$ as such: $\hat y=avgY+m(x-avgX)$ $\hat y=avgY-m.avgX~+mx$ i used the spreadsheet to make all these calculations m = 2.356 avgY-m.avgX = 268.040

16. amistre64

now i dont know what your program is wanting as far as how many decimal places to rnd to

17. amistre64

i cut it off at 3 decimals

18. amistre64

and I have no idea what this is refering to: Use the significance level of 0.05

19. anonymous

So, it should then say ŷ = (2.356 ) + ( 268.04)x

20. amistre64

that is what i would use for it, but again, i dont know what your course uses as a rnding of decimals. I used 3 places.

21. anonymous

it says two decimal places

22. amistre64

ŷ = (avgY-m.avgX ) + (m)x ŷ = (268.04 ) + ( 2.36)x

23. anonymous

Ugh it said it wasn't right

24. amistre64

the equation itself is all i can answer to, the rest of it ... i havent a clue about.

25. anonymous

did you find the best predicted value?

26. amistre64

y^ is the best predictor

27. amistre64

when we formulate the regression line, we then use it for x=96

28. amistre64

well, 92 in this case

29. amistre64

if i had excel, it would allow me to verify the line, but i have something else on this computer ... guess i can use a website

30. anonymous

ŷ = (47.87 ) + ( 0.25)x what about from this?

31. amistre64

ok, an online calculator says ive got an error in the y intercept slope is fine tho

32. amistre64

got it now, i erred in multiplyng :) y = m(x-X) + Y y = mx -mX + Y ^^^^ i ignored the negative of it

33. amistre64

this is the correction y = 2.36x - 73.54