Statistical Inference Review

Front

What is the mean of the sample proportion (p-hat) when 70% of credit card users do not pay their bill in full?

Back

Mean = 0.70

Front

What is the standard deviation of the sample proportion (p-hat) for a sample size of 2,100 when 70% of credit card users do not pay their bill in full?

Back

Standard deviation = 0.01

Front

What condition must be met for the sampling distribution of p-hat to be approximately normal?

Back

n*p and n*(1-p) must both be greater than 10.

Front

What is a parameter in statistics?

Back

A parameter is a numerical characteristic of a population, such as the population mean or standard deviation.

Front

What is the z-score?

Back

The measure of distance from the mean in terms of standard deviation.

Front

What is the formula for calculating a 95% confidence interval for the mean?

Back

CI = sample mean ± (z* * (population standard deviation / √n))

Front

What does a confidence interval represent?

Back

A confidence interval provides a range of values that is likely to contain the population parameter.

Front

What is the significance of the sample size in statistical inference?

Back

Larger sample sizes generally lead to more accurate estimates of population parameters.

Front

What is the central limit theorem?

Back

The central limit theorem states that the sampling distribution of the sample mean will be approximately normally distributed if the sample size is sufficiently large.

Front

How do you interpret a z-score of 2?

Back

A z-score of 2 indicates that the value is 2 standard deviations above the mean.