QUIZ 8 REVIEW

A research company wants to estimate the proportion of people who like oatmeal.  They want the confidence level to be 95%.  The company gets 325 people to sign up for the survey, but on the day that the survey is issued, only 250 people show up and take the survey.  What happens to the confidence interval?

• It gets larger
• It gets smaller
• It stays the same
• Too little information given

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

Given the same mean, SD, and sample size, a confidence interval of 80% would be wider than a confidence interval of 90%

• True
• False

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

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. Round your answer to the nearest hundredth.

(a)  

A random sample of 100 visitors to a popular theme park spent an average of $142 on the trip with a sample standard deviation of $47.50. Which of the following would be the 75% confidence interval for the mean money spent by all visitors to this theme park?

(a)  

The heights (in inches) of adult males on a small Pacific Island are believed to be Normally distributed with an unknown mean μ. The average height of a random sample of 250 adult males from the island is found to be 69.72 inches, with a known population standard deviation of σ = 4.15 inches. A 99% confidence interval for μ is...

• (67 < μ < 72)

• (67 < μ < 72)

• (69 < μ < 70)

• (68 < μ < 71)

If the 95% Confidence Interval for a population mean is (114.56, 125.54), then is it likely that the true population mean µ is greater than 130?

• Yes

• No

• Not enough information

• I have no idea what you're asking of me

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.4

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. Find the margin of error for a 75% confidence interval, rounded to the nearest HUNDRETH

• 0.1146

• 0.115

• 0.1

• 0.11

A ___ is a small portion of the population used to gather data from.

• Systematic Sampling Method

• Sample

• Population

• Bias

When working with the sampling distribution of a sample statistic, which of the choices would decrease the margin of error?

• Increase the sample size.

• Decrease the sample size.

• Increase the standard error.

• Increase the standard deviation.

A sample data set, n = 110, shows human body temperatures with a mean of 98.4ºF. If the standard deviation σ is known to be 0.65ºF,

Find the margin of error for a 95% confidence level, round your answer to the nearest HUNDREDTH

(a)