Confidence Interval Review

What is confidence interval?

• A period of time in mathematics.

• An interval that always has 95% accuracy.

• A range of values we are confident that a value lies between

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

What does the displayed image show?

• The average rate of change.

• A normal distribution.

• A cubic function.

Tags

CCSS.HSF.IF.B.6

CCSS.HSS.ID.A.4

Which z-value is used for a 95% confidence interval?

• 2.58

• 2.33

• 1.96

• 1.28

Tags

CCSS.HSS.ID.A.4

When do we use t-distribution?

• When we don't have the standard deviation of the population.

• When the sample size is 10% of the population size.

• When the standard deviation of the population is 95% or higher.

• When the population size is greater than the sample size.

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

How does t-distribution compare to a Normal curve?

• closer together

• more spread

• they are equal distributed

Tags

CCSS.HSS.ID.A.3

What is the degrees of freedom equal to?

• n

• n + 1

• 1 - n

• n - 1

A sample of 40 people owned an average of 1.35 apple products. It is known from a previous study that the population standard deviation of apple product ownership is 0.63 products. Construct a 95% confidence interval.

• (1.15, 1.55)

• (1.04, 1.64)

• (1.23, 1.56)

• (1.12, 1.63)

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

CCSS.HSS.ID.A.4

We measure the height of 40 randomly selected women, in which the mean height is 175cm. We also know the standard deviation is 20cm. Which of the following represents a 95% Confidence Interval?

• 135cm ± 20cm

• 175cm ± 6.2cm

• 155cm ± 6.2cm

• 175cm ± 35cm

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

CCSS.HSS.ID.A.4

What is the t value associated with 90% confidence and a sample size of 15?

• 1.683

• 1.234

• 1.437

• 1.761

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 a sample of 20 cupcakes will find 250 calories per cupcake.

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

• None of the above.

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4