AP Stats

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. 
Is the sampling distribution approximately Normal?  (Check to see if the Large Counts condition is met). 

• Yes.

• No.

A simple random sample of 100 high school seniors in a certain suburb reveals that 65% of them have at least part-time jobs in addition to school. If the expected value of this proportion is equal to the proportion of high school seniors who have at least part-time jobs for the entire suburb, then we say that the sample proportion is:

• a true value.

• an unbiased estimator of the population proportion.

• equal to the population proportion.

• an estimate whose variance equals the variance of data in the population.

• less than the population proportion since only 100 students were sampled.

In a school of 2500 students, the students in a AP Statistics class are planning a random survey of 100 students to estimate the proportion who would rather drop soccer than band during this time of severe budget cuts. Their teacher suggests instead to survey 200 students in order to

• reduce bias.

• reduce variability.

• increase bias.

• increase variability.

• make possible stratification between soccer and band.

What does this formula do?

• Calculates Standard Deviation

• Checks if the samples are independent

• Checks Normality

• Calculates Probabilities

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

• The Population

• The Sample

• The Sampling Distribution

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

• The Population

• The Sample

• The Sampling Distribution

A group of 625 students has a mean age of 15.8 years with a standard deviation of 1.6 years. The ages are normally distributed. What is the probability that the mean age of 40 randomly selected student is at most 16.3 years old?

• 0.976

• 0.623

• 0.377

• 0.024

• Cannot be determined.

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

What happens to the shape of a sampling distribution of sample means as n increases?

• It becomes narrower and bimodal.

• It becomes narrower and more normal.

• It becomes wider and skewed right. 

• It becomes wider and more normal. 

Suppose we have a population that is 49% male.  If we take a random sample from that population and determine the percent of our sample that is male, we refer to this proportion as...

• p

• p-hat
  

• the sample mean

• the sampling distribution