Sampling Proportions and Means

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

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

When sampling from a population with proportion p, the distribution of sample proportions (p-hat) will vary. What will be the mean of all possible sample proportions?

• p

30% of all dogs in a city are micro-chipped. In a sample of 500 dogs, what is the probability that less than 32% of dogs are micro-chipped?

• 0.2586

• 0.1587

• 0.8354

• 0.1398

• 0

A bag contains chips of which 27.5 percent are blue. A random sample of 5 chips will be selected one at a time and with replacement. What are the mean and standard deviation of the sampling distribution of the sample proportion of blue chips for samples of size 5 ?

• The mean is 0.275, and the standard deviation is 0.250

• The mean is 0.275, and the standard deviation is 0.156

• The mean is 0.275, and the standard deviation is 0.275(0.725)5. 0.200.

• The mean is 0.275, and the standard deviation is 0.350

• The mean is 0.275, and the standard deviation is 0.1.00

Select the correct description

• Average Percent

• Population Proportion

• Sample Proportion

• Percent Slope of a Distribution

• True

• False

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 93% of 180 is > 10

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

What is the standard deviation of the distribution?

• 1010

• 20

• 60

• √20

Your mail-order company advertises that it ships 90% of its orders within three working days. You select an SRS of 100 of the 5000 orders received in the past week for an audit.

What is the mean?

• 0.9

• 0.1

• 500

• 450

• 0.5