Question

a class of si of size 20 from c) Describe a process you could use to get a simple random sample 40. odern Managed Hospitals (MMłl) is a national for-profit chain of hospitals. Management ain patient satisfaction profiles. They wish to wants to survey patients discharged this year to obt use a sample of such patients. Several sampling techniques are described below. Categorize each technique as simple random sample, stratified sample, systematic sample, cluster sample, or convenience sample. a) Obtain a list of patients discharged from all MMH facilities. Divide the patients according t length of hospital stay (2 days or less, 3- 7 days, 8-14 days, more than 14 days). Draw simple random samples from each group. b) Obtain lists of patients discharged from all MMH facilities. Number these patients, and then use a random-number table to obtain the sample. c) Randomly select some MMH facilities from each of five geographic regions, and then include all the patients on the discharge lists of the selected hospitals. d) At the beginning of the year, instruct each MMH facility to survey every 500oh patient discharged. e) Instruct each MMH facility to survey 10 discharged patients this week and send in the results. Section 1.3 8) Which technique for gathering data (sampling, experiment,simulation, or census) do you think was used in the following studies? a) An analysis of a sample of 31,000 patients from New York hospitals suggests that the poor and the elderly sue for malpractice at one-fifth the rate of wealthier patients (Journal of the American Medical Association) b) The effects of wind shear on airplanes during both landing and takeoff were studied by using complex computer programs that mimic actual flight., c) A study of all league football scores attained through touchdowns and field goals was conducted by the National Football League to determine whether field goals account for more scoring events than touchdowns. (USA Today)

Answer 1

Soln

Simple Random Sampling

If all possible samples of n objects are equally likely to occur, the sampling method is called simple random sampling.

Stratified sampling

The researcher divides the population into separate groups, called strata. Then, a probability sample (often a simple random sample ) is drawn from each group.

Stratified sampling has several advantages over simple random sampling. For example, using stratified sampling, it may be possible to reduce the sample size required to achieve a given precision. Or it may be possible to increase the precision with the same sample size.

Systematic Sampling

We create a list of every member of the population. From the list, we randomly select the first sample element from the first k elements on the population list. Thereafter, we select every kth element on the list.

Cluster Sampling

The researcher divides the population into separate groups, called clusters. Then, a simple random sample of clusters is selected from the population. The researcher conducts his analysis on data from the sampled clusters.

Compared to simple random sampling and stratified sampling , cluster sampling has advantages and disadvantages. For example, given equal sample sizes, cluster sampling usually provides less precision than either simple random sampling or stratified sampling. On the other hand, if travel costs between clusters are high, cluster sampling may be more cost-effective than the other methods.

Convenience Sample

A convenience sample is one of the main types of non-probability sampling methods. A convenience sample is made up of people who are easy to reach.

Consider the following example. A pollster interviews shoppers at a local mall. If the mall was chosen because it was a convenient site from which to solicit survey participants and/or because it was close to the pollster's home or business, this would be a convenience sample.

Ques 20)

a)

Stratified sampling

b)

Simple Random Sampling

c)

Cluster Sampling

d)

Systematic Sampling

e)

Convenience Sample

Ques 8)

a)

Sampling

b)

Simulation

c)

Sampling