To find the total cost for printing 200 invitations, we can use the provided equation:
\[ y = 3.12x + 3.30 \]
where \( x \) is the number of invitations and \( y \) is the total cost.
Substituting \( x = 200 \) into the equation:
\[ y = 3.12(200) + 3.30 \]
Now, calculate \( 3.12 \times 200 \):
\[ 3.12 \times 200 = 624 \]
Next, add the setup cost of $3.30:
\[ y = 624 + 3.30 = 627.30 \]
Therefore, the total cost for Betty to print 200 invitations is $627.30.