The following table shows a random sample of 12 couples who stated the number x of children they planned to have at the time of their marriage and the number y of actual children they have.
![750_number y of actual children they have.png](https://secure.tutorsglobe.com/CMSImages/750_number y of actual children they have.png)
a. Find the least-squares regression line of y on x.
b. Estimate the number of children that a couple who had planned to have 5 children actually had.