  Show Intro/InstructionsA political candidate has asked you to conduct a poll to determine what percentage of people support her. If thecandidate only wants a 5% margin of error at a 90% confidence level, what size of sample is needed?Hint: TextbookVideo +1

Question help_outlineImage TranscriptioncloseShow Intro/Instructions A political candidate has asked you to conduct a poll to determine what percentage of people support her. If the candidate only wants a 5% margin of error at a 90% confidence level, what size of sample is needed? Hint: Textbook Video +1 fullscreen
Step 1

Given:

Margin of error = 5%

Confidence level = 90%

Step 2

Z score corresponding to 90% confidence level = 1.645

(for 90% confidence level. alpha = 10% and alpha/2 = 5%, So Z (alpha/2) = 1.645)

Proportion p = 0.5 ( standard  assumption when p not given)

Note: If your textbook follows any other assumption for p, please use that value in place of 0.5

Step 3

n can be estimated using the formual shown and a...

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