Sampling Distributions

A study of 10,000 males who smoke at least two packs of cigarettes daily shows that the mean life span is 65.3 years while the std. dev. is 3.4 years.

Find the standard deviation of the sampling distribution given a random sample of 40 males.

• 3.4

• 0.54

• 1.5

• 0.88

The mean and standard deviation of a population are 200 and 20, respectively. Sample size is 35.  What is the mean of the sampling distribution?

• 200
• 16
• 25
• 4

The mean and standard deviation of a population are 200 and 20, respectively. Sample size is 35.  What is the standard deviation of the sampling distribution?

• 200
• 20

• 33.81

• 3.381

For what values of "n" and  $\rho$  will the sampling distribution of   $\rho$ -hat be approximately normal? 

• n=30;  $\rho$  =80%

• n=30;  $\rho$  =60%

• n=30;  $\rho$  =20%

• n=30;  $\rho$  =90%

A z-score tells you...

• the standard deviation of a sampling distribution.
• the original raw score on which it is based.
• if the distribution it comes from is normal.
• how many standard deviations away from the mean a score lies.

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

• The population distribution

• The sampling distribution

• The sample distribution

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

• The population distribution

• The sample distribution

• The sampling distribution

What happens to the shape of a sampling distribution of sample means as "n" increases?

• It becomes narrower and less normal
• It becomes narrower and more normal.
• It becomes wider and more normal 
• It becomes wider and less normal. 

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

Tags

CCSS.HSS.IC.A.1

CCSS.HSS.IC.B.3

The mean life span of a refrigerator is 105,120 hours and standard deviation is 17,520 hours.

Then, 68% of all refrigerators will have a life span between ___________ hours and __________ hours.

• 87,600 hours and 122,640 hours.

• 70,080 hours and 140,160 hours.

• 52,560 hours and 157,680 hours.

• 96,360 hours and 113,880 hours.