Confidence Intervals for One Mean (Z or T Mastery Check)

When interpreting the confidence interval, make sure that you are describing the 

• statistic
• parameter

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

A __________ gives an interval of plausible values for the _____________. 

• confidence interval, statistic
• point estimate, parameter
• point estimate, statistic
• confidence interval, parameter

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

Complete the equation for a confidence interval:

point estimate +/- _____

• standard deviation

• margin of error

• critical value

• confidence level

Tags

CCSS.HSS.IC.B.4

Given the interval (1.2, 1.8), what is the point estimate and the margin of error? 

• 1.5, 0.6
• 1.5, 0.3
• 1.2, 0.3
• 1.2, 0.6

Tags

CCSS.HSS.IC.B.4

A 90% confidence interval for the mean speed driven by cars on East Main St. is given by (21, 45). What was the sample mean of this study?

• 12
• 24
• 33
• None of these.

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

What is the format for interpreting a confidence interval? 

• The interval from ___ to ___ captures the true mean in context.
• C% of samples of the same size taken from the same population will capture the parameter in question
• There is convincing evidence that C% gives the interval (___, ___) capturing the parameter in question.
• We are C% confident that the interval from ___ to ___ captures the [parameter in context].

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

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

• We are 95% confident that the true mean calorie content can be found with a sample of 150 to 350 cupcakes.
• We are 95% confident that the true mean calorie content in cupcakes is between 150 and 350 calories.
• We are 95% confident that a sample of 20 cupcakes will find 250 calories per cupcake.
• None of these are correct.

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

Increasing the sample size __________ the confidence interval. 

• increases
• decreases
• does not affect
• there is not enough evidence to determine the answer

Tags

CCSS.HSS.IC.B.4

What can you do to reduce the margin of error? 

• increase the confidence level
• decrease the confidence level
• increase sample size
• decrease sample size

Tags

CCSS.HSS.IC.B.4

What is the degrees of freedom equal to?

• n
• n+1
• 1-n
• n-1