Attempt following question by selecting a choice to answer.
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A fast-food restaurant owner wishes to estimate the average number of people visiting the restaurant. He wants to be 90% confident that the estimate is within 5 percentage of the true proportion. How large should the sample size be?
cccc ccccA.
c1,089
B.
c545
C.
c273
D.
c33
cc
C
Step 1: For 90% confident interval, zα/2 is 1.65.
[Use the standard normal distribution table.]
Step 2: The maximum error of estimation allowed, E = 5% = 0.05
Step 3: Since pˆ is not given, assume pˆ as 0.5 and qˆ as 0.5.
Step 4: Sample size, n = pˆ qˆ (Zα/2E)2
[Minimum sample size.]
Step 5: n = (0.5) (0.5)(1.650.05)2
n = 272.25 ≈ 273
Step 6: So, a sample of 273 people is required.