I am trying to figure out what math equation I would use to predict seasonality for this math problem. I am not sure how to get started on this. My professor put ((Hint: When determining the solution to this question remember that amounts needed in a store will go up around holidays. Seasonality is a characteristic of a time series in which the data experiences regular and predictable changes that recur every calendar year. Any predictable change or pattern in a time series that recurs or repeats over a one-year period can be said to be seasonal.))

MATH PROBLEM:

Review the monthly data involving Fuji apples purchased at a large grocery store. Predict how many Fuji apples will need to be in stock to have available for the customers in December (month 12)?

Month Fuji Apples Purchased

1 5,325

2 5,648

3 5,873

4 9,842

5 8,234

6 9,421

7 10,123

8 9,784

9 10,443

10 9,564

11 10,147

12 ???