Download Introduction to Sampling Distributions Before the end of this chapter

Introduction to Sampling Distributions
Before the end of this chapter, make sure you can write a definition of each term below. You might complete
these are you move along in the chapter.
Parameter:
Statistic:
Sampling variability:
Sampling distribution:
Population distribution:
Unbiased estimator:
Variability of a statistic:
One of the most powerful skills we learn from statistics is the ability to answer a question about a population
characteristic based on information gathered from a random sample. We can use the statistic calculated from a
sample to make a conclusion about a corresponding parameter in the population. However, you must remember
that statistics we calculate vary from sample to sample and may differ from the population characteristic we are
trying to measure. The sample to sample variability can pose a problem when we try to generalize our finding
about a population. However, based on what we have already learned this year, we can view a sample statistics
as a random variable. With the probability distribution of this variable in mind, we can use a sample statistics
to estimate the population parameter.
For each of the following situations, identify the population of interest, the parameter, and the statistic:
a) A medical researcher is interested in exploring the effects of a new medicine on blood pressure. 500
males with high blood pressure are randomly selected and given the new drug. After two weeks, their
blood pressure is measured and the average arterial pressure is measured.
Population of interest _______________________________________________________________
Parameter ________________________________________________________________________
Statistic __________________________________________________________________________
b) A study is conducted to determine whether or not the dangerous activity of texting while driving is a
common practice. 1500 16 to 24 year-olds are randomly selected and asked whether or not they text
while driving. Of the 1500 drivers, 12% indicate they text while they drive.
Population of interest _______________________________________________________________
Parameter ________________________________________________________________________
Statistic __________________________________________________________________________