Estimating a Proportion & Confidence Interval for a Proportion

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What is a confidence interval?

Back

A confidence interval is a range of values that is used to estimate the true value of a population parameter with a certain level of confidence.

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What does the term 'parameter' refer to in statistics?

Back

A parameter is a numerical characteristic of a population, such as a mean or proportion.

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What is a point estimate?

Back

A point estimate is a single value that serves as an estimate of a population parameter.

Front

What is the margin of error in the context of confidence intervals?

Back

The margin of error is the amount added to and subtracted from the point estimate to create the confidence interval.

Front

How do you calculate a confidence interval for a proportion?

Back

The confidence interval for a proportion is calculated using the formula: point estimate ± margin of error.

Front

What is the critical value (z*) in statistics?

Back

The critical value (z*) is a multiplier that determines the width of the confidence interval based on the desired confidence level.

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What is the Large Counts condition?

Back

The Large Counts condition states that both np and n(1-p) must be greater than or equal to 10 to use the normal approximation for a proportion.

Front

How do you find the critical value for a 94% confidence interval?

Back

For a 94% confidence interval, the critical value (z*) is approximately 1.881.

Front

What is the relationship between confidence level and critical value?

Back

As the confidence level increases, the critical value (z*) also increases, resulting in a wider confidence interval.

Front

What is the formula for calculating the margin of error for a proportion?

Back

The margin of error for a proportion is calculated as: z* × sqrt( (p(1-p))/n ), where p is the sample proportion and n is the sample size.