Confidence Intervals

Find the confidence interval for a mean of 142.5 and a margin of error of 5.2.

• (5.2, 142.5)

• (137.5, 142.5)

• (142.5, 147.5)

• (137.3, 147.7)

A sample of 20 cupcakes found the interval for average calories to be (150, 350). Which is the correct interpretation of the 95% confidence interval?

• We are 95% confident that the true mean caloric content can be found with a sample of 150 to 350 cupcakes.

• We are 95% confident that the interval (150, 350) captures the true average caloric content.

• We are 95% confident that a sample of 20 cupcakes will find 250 calories per cupcake.

• None of these are correct.

Between a Population and Sample: which size is bigger ?

• Population

• Sample

• Both can be the same

• Not enough information

What is the lowest recommended confidence interval one should use to predict the population mean?

• 90%

• 95%

• 50%

• any percentage is fine

If using a 95% confidence level, what value of z should you use?

Which symbol represents the mean of a sample?

If using a 99% confidence level, what value of z should you use?

Set of methods to obtain data and then organize, summarize, present, analyze, interpret and reach conclusions based on the data

• Statistics

• Inferential Statistics

• Descriptive Statistics

These are the two types of statistics:

• Discrete and Continuous

• Population and Sample

• Descriptive and Inferential

• Mean and Standard deviation

If the mean of a sample is 203 and the margin of error is 4.6, what would be a reasonable mean for the population?

• 99.2

• 198.3

• 207.2

• 207.7