Have you plttoed these points? They do make a perfect straight line therefore you can avoif using the least squares regression method and just make a linear function in the form of y=mx+c by substituting in some of your values
If x is 1,2,3,4 and y is -1/4, -1/2, -3/4, -1 (table format)
How would the values of this table be interpreted in terms of linear regression?
I was able to determine that 1 was the missing value of y.