Question 755874
Q:
Approximately 20% of U.S. residents are left-handed. If 100 residents are selected at random, would it be unusual to find that more than 30% are left-handed? Explain your reasoning and show calculations.
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A:
X~Binomial(100, 0.2)
P(X > 30) = {{{sum((matrix(2,1,100,x))(0.2^x)(0.8^(100 - x)), x = 31, 100)}}} = {{{highlight(0.0060593)}}}
Since the probability is less than 0.05, then it would be unusual to find that more than 30% are left-handed.