Final answer:
To find a cosine curve that models the data, we can use the formula y = A cos(B(x - C)) + D, where A, B, C, and D represent different factors. By performing the regression analysis on the given data, we can find the cosine curve that models the average daily sunspot count for the years 1975-2004.
Step-by-step explanation:
To find a cosine curve that models the data, we can use the formula:
y = A cos(B(x - C)) + D
where A represents the amplitude, B represents the period, C represents the phase shift, and D represents the vertical shift.
In this case, we are given a table of data with years and sunspot counts. We can use regression analysis to estimate the values of A, B, C, and D that best fit the data.
By performing the regression analysis on the given data, we can find the cosine curve that models the average daily sunspot count for the years 1975-2004.