Sampling Distributions of Means and Proportions

A manufacturer of cell phone batteries claims that the average number of recharge cycles for its batteries is 400. A consumer group will obtain a random sample of 100 of the manufacturer’s batteries and will calculate the mean number of recharge cycles. Which of the following statements is justified by the central limit theorem?

• The distribution of the number of recharge cycles for the sample is approximately normal because the population mean of 400 is greater than 30.

• The distribution of the number of recharge cycles for the sample is approximately normal because the sample size of 100 is greater than 30.

• The distribution of the number of recharge cycles for the population is approximately normal because the sample size of 100 is greater than 30.

• The distribution of the sample means of the number of recharge cycles is approximately normal because the sample size of 100 is greater than 30.

• The distribution of the sample means of the number of recharge cycles is approximately normal because the population mean of 400 is greater than 30.

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

• The Population

• The Sample

• The Sampling Distribution

Tags

(SR.DSR.4.3

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

Tags

(SR.DSR.4.3

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

Tags

(SR.DSR.4.3

The mean and standard deviation of a population are 200 and 20, respectively. 
What is the probability of selecting 100 data values with a mean greater than 202?

• 45%

• 36%

• 25%

• 16%

Tags

(SR.DSR.4.3

28% of all Dacula students believe Monday will be a 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

Tags

(SR.DSR.4.3

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

• The Population

• The Sample

• The Sampling Distribution

Tags

(SR.DSR.4.3

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.  We will count the number of people in the sample who attended church.  A newspaper report claims that 40% of all U.S. adults went to church last week.  What type of analysis would we do?

• Proportion

• Means

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. In order to do this problem, you would need to use the formulas for...

• proportions

• means