Yes the answer is c. z=3 or z=-9
She underestimated by 60 cents. To get this answer all you need to do is multiply 1 dollar times 12 which is $12 and then multiply $.30 by 12 and that gives you $3.60. Then you add the $12 to the $3.60 and that gives you $15.60 which is 60 cents over the estimation.
True all table does not need to include numerical data
Your answer is B Hope I helped :)