Confidence Intervals (with proportions)

The amount added and subtracted to the statistic.

• Margin of Error

• Point Estimator

• Statistic

• Population

Tags

CCSS.HSS.IC.B.4

Which of the following changes to a study would result in a narrower confidence interval?

• increasing the confidence level, increasing the sample size

• decreasing the confidence level, decreasing the sample size

• increasing the confidence level, decreasing sample size

• decreasing the confidence level, increasing the sample size

Tags

CCSS.HSS.IC.B.4

A 90% confidence interval for the average salary of all CEOs in the electronics industry was constructed using the results of a random survey of 45 CEOs. The interval was ($139,048, $154,144). Give an interpretation of the interval.

• 90% of the sampled CEOs have salaries that fell in the interval $139,048 to $154,144

• We are 90% confident that the mean salary of all CEOs in the electronics industry falls in the interval $139,048 to $154,144

• 90% of all CEOs in the electronics industry have salaries that fall between $139,048 to $154,144

• We are 90% confident that the mean salary of the sampled CEOs CEOS falls outside of the interval $139,048 to $154,144

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

Which of the following values below represents the critical value for a 98% confidence interval?

• 2.326

• 2.054

• 1.645

• 3.091

Tags

CCSS.HSS.ID.A.4

The confidence level of an interval estimate of a parameter is the probability that the interval estimate will contain the parameter.

• true

• false

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

CCSS.HSS.ID.A.4

Find the value z_c for a 90% confidence interval.

• -1.96

• 1.64

• 1.44

• -1.59

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

CCSS.HSS.ID.A.4

Given the same scenario, a confidence interval of 80% would be wider than a confidence interval of 90%

• True

• False

Tags

CCSS.HSS.ID.A.4

An IQ test was given to a simple random sample of 75 students at a certain college. The sample mean score was 105.2. Scores on this test are known to have a standard deviation of 10. It is desired to construct a 90% confidence interval for the mean IQ scores of the students at the college.

Find the critical value

• 0.90

• 1.64

• 105.2

• 1.15

Tags

CCSS.HSS.IC.B.4

CCSS.HSS.IC.A.1

CCSS.HSS.ID.A.4

Find the critical value for an 86% Confidence Level.

• -1.46

• 1.28

• -1.28

• 1.48

Tags

CCSS.HSS.ID.A.4

Complete the equation: 

point estimate +/- _____

• margin of error

• standard deviation

• critical value

• confidence level

Tags

CCSS.HSS.IC.B.4