Sampling Distributions Stats

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

• 200
• 16
• 25
• 4

A statistic is an unbiased estimator of a parameter when

• the statistic is calculated from a random sample.
• in many samples, the values of the statistic are very close to the value of the parameter.
•  in a single sample, the value of the statistic is equal to the value of the parameter
• in many samples, the values of the statistic are centered at the value of the parameter.

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

In the game of Scrabble, each player begins by drawing 7 tiles from a bag containing 100 tiles.  There are 42 vowel, 56 consonants, and 2 blank tiles in the bag.  Cait chooses an SRS of 7 tiles.  Let p-hat be the proportion of vowels in her sample. 
Is the 10% condition met in this case?

• Yes.
• No.
• Not enough info to determine.

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 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.  (Check to see if the 10% condition is met first)

• 0.0116
• 0.0117
• 0.0118
• 0.0119

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

Why do we randomly select our samples?

• for control
• reduce bias
• so we don't get the same answers from everyone
• to eliminate confounding results

The population describes:

• The group of people, objects or events being surveyed
• part of the group being surveyed
• the whole world
• the school