Statistics - Chapter 8 Review

Front

What is a 95% t interval?

Back

A 95% t interval is a range of values used to estimate the true population mean with 95% confidence, based on sample data and the t-distribution.

Tags

CCSS.HSS.IC.B.4

Front

What conditions are necessary for a 95% t interval to be valid?

Back

1. The sample must be randomly selected from the population. 2. The population standard deviation is unknown. 3. The population should be approximately normal.

Tags

CCSS.HSS.IC.B.4

Front

What does it mean if n*p-hat > 10 and n(1 - p-hat) > 10?

Back

These conditions ensure that the sample size is large enough for the normal approximation to the binomial distribution to be valid.

Tags

CCSS.HSS.ID.A.4

Front

How do you find the value of t* for a confidence interval?

Back

The value of t* can be found using a t-distribution table based on the desired confidence level and degrees of freedom (n-1).

Tags

CCSS.HSS.ID.A.4

Front

What is the effect of increasing the confidence level on the width of a confidence interval?

Back

Increasing the confidence level results in a wider confidence interval, as it requires a larger margin of error to ensure greater certainty.

Tags

CCSS.HSS.IC.B.4

Front

What is the margin of error in a confidence interval?

Back

The margin of error is the range within which the true population parameter is expected to lie, calculated as the product of the critical value and the standard error.

Tags

CCSS.HSS.IC.B.4

Front

What is the significance of a boxplot having a large outlier?

Back

A large outlier in a boxplot indicates that the data may not be normally distributed, which can affect the validity of statistical inferences.

Front

What happens to the confidence interval if the sample size is decreased?

Back

Decreasing the sample size increases the width of the confidence interval, leading to a larger margin of error.

Tags

CCSS.HSS.IC.B.4

Front

What is the formula for calculating the sample size needed for a specific margin of error?

Back

n = (Z*sigma/M)^2, where Z is the z-score for the desired confidence level, sigma is the population standard deviation, and M is the margin of error.

Tags

CCSS.HSS.IC.B.4

Front

What is a Normal probability plot?

Back

A Normal probability plot is a graphical tool used to assess if a dataset follows a normal distribution by plotting observed values against expected values.