Help Me!!!!!! I am so confused!!!! Needs Attention!!!?

Question

2. Determine the slope of the line that passes between the two points you’ve selected. (Hint: To set up points, let January of 05 be month 1, February of 05 month 2, and so on.) (3 points)
3. Substitute the coordinates of one point and the slope you calculated in step two into the point-slope equation of a line: y – y1 = m(x – x1).
Solve for y to get the form: y = mx + b. (3 points)
4. Clearly state what your variables represent. (Note: the collaborative investigation on page 459 might be helpful to develop a linear model.) (3 points)
5. Use your model, the equation you’ve developed, to predict the CPI for the next month. (3 points)
Consumer Prices Index
Food in Spain
Base 2006=100
Beginning January 2005
Source:INE Instituto Nacional de Estadística (España)
Copyright INE 2007


Month Food Index
Jan-05 94.934
Feb-05 94.778
Mar-05 95.123
Apr-05 95.805
May-05 95.874
Jun-05 95.895
Jul-05 95.641
Aug-05 95.979
Sep-05 96.188
Oct-05 96.408
Nov-05 97.012
Dec-05 98.296
Jan-06 99.227
Feb-06 98.911
Mar-06 98.926
Apr-06 99.144
May-06 99.341
Jun-06 99.892
Jul-06 100.309
Aug-06 100.463
Sep-06 100.776
Oct-06 100.722
Nov-06 100.87
Dec-06 101.42
Jan-07 101.559
Feb-07 101.359
Mar-07 101.723
Apr-07 102.343
May-07 102.471

I chose months1 Feb-05 and Feb-07 to work with! Help due in 2 hours.

Answer 1

Pick months 1 and 3 giving slope = (95.123-94.934)/(3-1)
slope = ..0945

y - 94.934 = .0945(x-1)
y = .0945x -.0945 +94.934
y = .0945x + 94.8395

x = the number of months starting with January of 2005
y = the the Food index for month x

y = .0945*30 + 94.835 = 97.67 + food index for June 07
Doesnn't seem to be a very good prediction.