Question

In a recent poll, 390 people were asked if they liked dogs, and 76% said they did. Find the Margin of Error for this poll, at the 95% confidence level. Give your answer to four decimal places if possible.

Answer 1

Solution :

The margin of error to estimate the population proportion with 95% confidence level is given as follows :

Where, Z_(0.05/2) is critical z-value (two-tailed) at 95% confidence level, p̂ is sample proportion and n is sample size.

Sample proportion of people who liked dogs is, p̂ = 76% = 0.76

n = 390

Using Z-table we get, Z_(0.05/2) = 1.96

Hence, the margin of error at 95% confidence level is,

Hence, the margin of error for the poll is 0.0424.

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