AP Statistics Sampling

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. 
What is the mean of the sampling distribution of p-hat?

• 0.4

• 0.44

• 0.56

• 0.6

The mean and standard deviation of a population are 200 and 20, respectively. Sample size is 25. 
What is the standard deviation of the sampling distribution?

• 200

• 16

• 25

• 4

The average cost for a gallon of gasoline is $2.51 (source AAA.org) with a standard deviation of $0.42. Find the mean and standard error of the sampling distribution if n is decreased to 25.

• μ_x-bar = 2.51, σ_x-bar = 0.06

• μ_x-bar = 2.51, σ_x-bar = 0.084

• μ_x-bar = 0.52, σ_x-bar = 0.084

• μ_x-bar = 2.51, σ_x-bar = 0.42

The mean weight of potato chip bags is 10.5 ounces with a standard deviation of 3 ounces. A random sample of 40 bags of potato chips is selected. What is the probability that the mean of the sample is less than 10 ounces?

• P = -1.05

• P = .1469

• P = .0202

• P = .8531

The mean distance an OHS student travels to school is 5.6 miles with a standard deviation of 1.7 miles. Mrs. McLemore finds the mean of her 4th period class - a randomly selected sample of 29 students. What is the probability that the mean of her class is more than 6 miles?

• P = 0.00

• P = 0.1020

• P = 0.8980

• P = 1.27

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

If you are to find P (x̄ ≥ 10) that means

• the probability that the sample mean is less than 10

• the probability that the sample mean is no more than 10

• the probability that the sample mean is at least 10

• the probability that the sample mean is more than 10

According to the Center for Disease Control, 93% of children entering kindergarten in the U.S. are vaccinated. A school district has 180 incoming kindergarten children.

Which of the following is true concerning the shape of the sampling distribution?

• The sampling distribution is normal because n > 30

• The sampling distribution is not normal because nq is < 30

• The sampling distribution is normal because 10% of 180 is > 10

• The sampling distribution is normal because np and nq are both > 10

According to a television commercial, 3 out of 4 dentists recommend Trident gum for patients who have dental work. A consumer magazine has surveyed 100 dentists to see if this claim is true. Which is closest to the probability that between 70 and 74 percent of the dentists recommend Trident?

• .9238

• .2846

• -.2846

• .0762

A statistic is biased if...

• the value of the statistic from any sample is NOT equal to the parameter

• The value of the statistic from any sample IS equal to the parameter

• The mean of the sampling distribution is NOT equal to the true value of the parameter

• The mean of the sampling distribution IS equal to the vali