Question 1065438
we use the following formula for margin of error(ME)
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ME = z * s / square root(n) where z is the z-score we use to calculate the confidence interval, s is the standard deviation, n is sample size and ME is the desired margin of error
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we want a 90% confidence interval(CI)
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alpha(a) = 1 - (90/100) = 0.10
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critical probability(p*) = 1 - (a/2) = 0.95
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z-score associated with p* is 1.644853
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15 = (1.644853) * 195) / square root(n)
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square root(n) = 320.746335 / 15
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n =  457.2365 approximately 457
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answer is C
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