AP Statistics

These symbols represent the mean and standard deviation for which of the following distributions?

• The Population

• The Sample

• The Sampling Distribution

The Gallup Poll asked a random sample of 1785 adults whether they attended church during the past week.  Let p-hat be the proportion of people in the sample who attended church.  A newspaper report claims that 40% of all U.S. adults went to church last week.  Suppose this claim is true. 
Calculate the standard deviation of the sampling distribution. 

• 0.0116

• 0.0117

• 0.0118

• 0.0119

28% of all Woodrow students believe Monday will be snow day. You take a sample of 50 students and find that 15 of them believe Monday will be a snow day. (The sample proportion is 15/50 or .3) What is the probability of getting a sample of size 50 that has 15 or more students who believe Monday will be a snow day?

• 0.376

• Cannot be determined because the distribution of the sample proportion of samples of size 50 is not normal

• 0.624

• 0.99999

78% of flights on major airlines arrive on time. A random sample was taken of 100 flights. Find the probability that more than 70% of the 100 randomly selected flights are on time.

• 0.5077

• 0.0267

• 0.9999

• 0.9733

Is this a probability distribution?

• No, the sum of p(x) does not equal 1.

• Yes, all p(x) are between 0 and 1.

• No, all p(x) are not between 0 and 1.

• Yes, the sum p(x) is 1.

• A

• B

• C

• D

• E

Is this a probability distribution?

• No

• Yes

28% of all Woodrow students believe Monday will be snow day. You take a sample of 50 students and find that 15 of them believe Monday will be a snow day. What does 50 represent? 

• n

• P

• phat

• standard deviation

These symbols represent the mean and standard deviation for which of the following distributions?

• The Population

• The Sample

• The Sampling Distribution

At a particular college, 78% of all students are receiving some kind of financial aid.The school newspaper selects a random sample of 100 students and 72% of the respondents say they are receiving some sort of financial aid. Which of the following is true?

•  78% is a population and 72% is a sample.

• 72% is a population and 78% is a sample

• 78% is a parameter and 72% is a statistic

• 72% is a parameter and 78% is a statistic