Experiment Problem... please help.

Another Experiment is performed using coins. This time, the experimenter starts with 4 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

Part A: Graph the results. DONE

Part B: Explain why the graph appeears exponential..
Part C: State an exponential equation that best fits the results. (use n to represent the number of the toss.)
Part D: State the equation that would predict the number of remaining coins if you began with N0 coins.
Part E: Perform the experiment yourself. Graph your results with a different colour.
Part F: The experimenter claims that the equation is explained by the formula for compound interest: A = P(1 + i)n. She argues that P represents the number of coins she started with, i is 0.5 since the growth rate is about 50% (since about one-half of the coins tossed come up heads) and N is the number of tosses, which is like the compounding period.

If her hypothesis is correct, create a formula that predicts the total number of coins if an unfair (weighted) coin is used that only comes up heads 1 out of every 4 times.
ThankYou soo much, need some serious help on this one