AP Statistics T Intervals

For a sample, the 95% confidence interval is (0.202, 0.482). What is the point estimate, p̂, of this sample?

• 0.28

• 0.14

• 0.342

• 0.684

What is the margin of error of this sample?

• 0.28

• 0.14

• 0.342

• 0.684

If 827 represents "no" voters out of 2584, construct a 95% confidence interval for the "no" group.

• [.300,.340]

• [.298,.342]

• [.302,.338]

• [.288,.352]

The symbol for the sample proportion is __________.

• Z_c

• p̂

• E

• q

A random sample of 100 WHS students found that 53 of them were in possession of a pencil. What is the p-hat for this sample?

• 0.53

• 0.5

• 0.47

• 1

To test a claim about a mean, when the population standard deviation is unknown we use:

• z procedures

• Pythagorean Theorem

• t procedures

• np > 10 and n(1-p) > 10

Margin of error equals:

• Critical Value ∗ standard Error

• z*

• 1.96

• Standard Error

What do we use to estimate unknown parameters?

• Hypothesis Test

• Confidence Interval

• Trig Identity

• Guess and check

2000 children were surveyed and the report that followed said, "With 98% confidence, between 20% and 50% of all parents make their children eat breakfast." What does 98% confidence mean in this situation?

• We can be 98% confident that the method used to get the intervals always gives the correct answer

• 98% of all parents will make their kids eat breakfast

• When used repeatedly, the method used to find the interval produces intervals which include the true proportion about 98% of the time

• The kids were 98% confident that they ate breakfast that day.

An irate patient complained that the cost of a doctor's visit was too high.  She randomly surveyed 20 other patients and found that the mean amount of money they spent on each doctor's visit was $44.80.  The standard deviation of the sample was $3.53.  Find the 95% confidence interval of the population mean.

• $43.15 - $46.45

• $44.53 - $48.21

• $42.65 - $48.25

• $43.15 - $48.25