Review for Exam 3 - Stats

Match the answers

• descriptive statistics

• number of standard deviations from the sample mean to the assumed u

• level of significance, α

• the probability (assuming Ho is true) of finding a sample mean as extreme as we did

• inferential statistics

• the total area of the rejection region

• test statistic, z

• 1. gathers, summarizes, and communicates data about a sample

• p-value

• 1. uses sample data to generalize about the population

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.

What is the point estimate?

• 75

• 105.2

• 10

• 0.90

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

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 critical value z* for a 99% confidence interval? 

• -2.58
• 1.96
• -1.64
• 2.58

Tags

CCSS.HSS.ID.A.4

Using the same data, Hank calculated a 95% confidence interval and Maria calculated a 99% confidence interval. Which interval is wider?

• Hank's

• Maria's

• They used the same data so they are the same width.

• Cannot be determined.

Which of the following is a property of the t-distribution?

• Used when sigma is known
• Based on degrees of freedom
• Positively skewed
• None of these

Tags

CCSS.HSS.ID.A.4

If n = 80 and x = 40 find p̂

• 2
• 0.2
• 0.5
• 4

What is the best point estimate for the population mean?

• Sample mean
• Sample median
• Sample proportion
• Sample mode

What is the best point estimate for the population proportion?

• sample mean

• sample standard deviation

• sample proportion

• sample median

Tags

CCSS.HSS.IC.B.4