MATH
posted by joe .
Hello,
In a class of 24 students, every student flips fairly two coins 40 times each and records the results. Assume that the class obtained the expected results when they conducted the experiment.
a. Make a bar graph illustrating the combined class results
b. explain why an individual student's results might be different from the class results.
I'm really unsure where to begin. This is a review for our state test and it makes me nervous.

a. The combined class results should be 50% heads and 50% tails. Best I can tell, your bar graph would have only 2 bars, both at 50%.
b. The law of large numbers basically says that the more times a probabilistic event is attempted, the closer the outcome (empirical probability) will come to the predicted outcome (theorectical probability). So the class's 480 tosses is more likely to hit the expected 50/50 ratio of heads to tails than is an individual student's 40 tosses, due solely to chance ("random fluctuations"). 
Esye