Sample Mean and Sample Proportion

10% of people are left handed. If 800 people are randomly selected, find the likelihood that at least 12% of the sample is left handed.

• 0.0297

• 0.0106

• 0.0409

• 0.0816

10% of people are left handed. Of the following, what is the smallest sample size needed to be at least 90% sure that the sample proportion will be between 9% and 11%?

• 1500

• 2000

• 2500

• 3000

Which of the following is the central limit theorem used for?

• The standard deviation of the distribution of sample means is found by dividing the population standard deviation by n.

• The distribution of sample means will be approximately normal if the sample size is at least 30.

• The distribution of sample proportions is approximately normal if both np and n(1 - p) are greater than or equal to 10.

• As sample size increases, variability decreases.

A company has 500 employees and wants to evaluate a proportion using the distribution of sample proportions and normal curve. Under which circumstance will they be able to do this?

• n = 80, p = .2

• n = 40, p = .2

• n = 40, p = .9

• n = 30, p = .4

It is computed by getting the weighted average of all possible values of a random variable.

• mean

• variance

• standard deviation

• binomial distribution

Given an SRS of 30 math scores, what is an estimate of the true proportion of students in this population that score over 650 in math?

• One-Proprtion z-Test

• One-Proportion z-Interval

• One-Sample t-Interval

• One-Sample t-Interal on Matched Pairs

Given an SRS of 20 math scores. Do we have reason to believe that the true proportion of students who score below 600 in math is not 50%?

• One-Proportion z-Test

• One-Sample t-Test

• One-Sample t-Test on Matched Pairs

• Two-Proportion z-Test

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

• The Population

• The Sample

• The Sampling Distribution

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. 

• 0.0116

• 0.0117

• 0.0118

• 0.0119

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