Writing an exponential equation

Another experiment is performed using coins. This time, the experimenter starts with four coins. Each time she tosses the coins into the air, she counts the number of heads that appear, then adds that number of coins to the amount she previously had. The following table shows her results.

Toss | Number of heads | Coins |

0 | | 4 |

1 | 2 | 6 |

2 | 3 | 9 |

3 | 5 | 14 |

4 | 7 | 21 |

5 | 10 | 31 |

a)Explain why the graph appears exponential

b)State an exponential equation that best fits the results. (Use *n* to represent the number of the toss.)

c)State the equation that would predict the number of coins after each toss if you began with *N*_{0} coins.

Jutneed some help, Thank You so much!(Evilgrin)(Evilgrin)(Evilgrin)(Cool)