Sampling Distributions Means and Proportions

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

A realtor has been told that 43% of homeowners in a city prefer to have a finished basement. She surveys a group of 300 homeowners randomly chosen from her client list. Describe the sampling distribution model of the proportion of homeowners in this sample who prefer a finished basement.

• mean = 43%; standard deviation = 1.4%

• mean = 57%; standard deviation = 2.9%

• mean = 57%; standard deviation = 1.4%

• mean = 43%; standard deviation = 2.9%

• There is not enough information to describe the distribution.

28% of all Suncoast students believe in Santa. You take a sample of 50 students and find that 15 of them believe in Santa. What does 15/50 represent?

• n

• P

• phat

• standard deviation

According to data from the United States Elections Project, only 36 percent of eligible voters voted in the 2014 elections. For random samples of size 40, which of the following best describes the sampling distribution of ps, the sample proportion of people who voted in the 2014 elections?

• The sampling distribution is skewed to the left, with mean 0.36 and standard deviation 0.076.

• The sampling distribution is skewed to the right, with mean 0.64 and standard deviation 0.006.

• The sampling distribution is approximately normal, with mean 0.36 and standard deviation 0.076.

• The sampling distribution is approximately normal, with mean 0.36 and standard deviation 0.006.

• The sampling distribution is approximately normal, with mean 0.64 and standard deviation 0.076.

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

Knowing that the result of flipping a coin is equally likely (that means, 50/50 chance of observing either outcome). If you flip a coin 500 times, approximate the probability that at least 51% of them will be Tails.

• Essentially 0.

• 0.2891

• 0.3274

• 0.8512

• 0.8236

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

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 standard deviation?

• 0.04

• 0.004

• 0.3

• 0.03