Question 281078
About 70% of the students at Fairview Technical College favor a new policy regarding parking on campus. Suppose we are interested in the proportion of 50 students in a matt class who favor the poilcy.
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Sketch a Normal curve with "p" as the label of the horizontal axis.
Put 0.7 on a middle-point of the axis.
Put sqrt(0.7*0.3/50) = 0.0648 under 0.7 so you remember the standard deviation.
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What is the probability that the proportion of the class who favor the policy is one-half or more?
z(0.5) = (0.5-0.7)/0.0648 = -3.0864
P(phat >=0.5)= P(z > -3.0864) = 0.9990
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What is the probability that the proportion of the class who favor the policy is between 60% and 80%?
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z(0.6) = (0.6-0.7)/0.0648 = -1.5432
z(0.8) = 1.5432
P(0.6 < phat <0.8) = P(-1.5432 < z < 1.5432) = 0.8772
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What is the probability that the proportion of the class who favor the policy is less than 60%?
Can you handle this now?
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Cheers,
Stan H.