A town has 10,000 two-child families. Design a simulation to estimate the percentage of two-child families with two girls. Choose a simulation tool, explain one trial, and describe the headings for a table in which you would record the outcomes. The simulation tool could be a coin flip, with heads up representing a girl and tails up representing a boy. One trial would require flipping the coin twice. One table would show the outcome of two coin tosses as tally marks, and indicate whether the results were boy-boy, boy-girl, or girl-girl.