Question

In a recent poll, 180 people were asked if they liked dogs, and 11 % said they did. Find the margin of error of this poll, at the 90% confidence level. Give your answer to three decimal places.

Answer 1

To find the margin of error of a poll at the 90% confidence level, we can use the formula: Margin of Error = Z x √((p x (1-p))/n). The margin of error of this poll at the 90% confidence level is approximately 0.033.

Step-by-step explanation:

To find the margin of error of a poll, we can use the formula:

Margin of Error = Z x √((p x (1-p))/n)

Where:

• Z is the z-score based on the desired confidence level
• p is the proportion of people who said they liked dogs in the poll (11% or 0.11)
• n is the sample size (180)

Since the confidence level is 90%, the z-score is 1.645 (corresponding to a cumulative probability of 0.95)

Plugging in these values into the formula we get:

Margin of Error = 1.645 x √((0.11 x (1-0.11))/180)

≈ 0.033

Therefore, the margin of error of this poll at the 90% confidence level is approximately 0.033.