1.4 Hw Stat

a study is conducted to measure children's growth rates without any treatment applied to the children. What best classifies this study?

An observational study involves observing and measuring specific characteristics without attempting to modify the subjects being studied.

determine whether the description correspond to an observational study or an experiment Research is conducted to determine if there is a relation between hearing los and exposure to mumps

observational study

Identify the type of sampling used (random, systematic, Convenience, stratified or cluster sampling) in the situation described below: in a poll conducted by a certain research center, 887 adults were called after their telephone number were randomly generated by a computer and 4% were able to correctly identify the vice president

random sampling

identify the type of observational study a researcher plans to obtain data by examining the financial transactions of victims who perished in a hurricane

retrospective

determine whether the sample described below is a simple random sample a quality control engineer selects every 6000th hairdryer that is produced

the sample is not a simple random sample because every sample of the same size does not have the same chance of being selected

determine whether the description correspond to an observational study or an experiment in a survey sponsored by a company, 12,954 people were asked what contributes most to their happiness and 76% of the respondents said that it was their health.

the study is an observational study because the survey subjects were not given any treatment

what is the difference between a random sample and a simple random sample

With a random sample, each individual has the same chance of being selected. With a simple random sample, all samples of the same size have the same chance of being selected.

Does this sampling plan result in a random sample an analysts processes one item every 10 minutes, so 240 items are completed in his first week of work. His manager cheeks his work by randomly selecting a day of the week, then reviewing all the items he completed that day. Does this sample plan result in a random sample? Simple random sample? Does this sampling plan result in a simple random sample?

Yes, because each item has an equal chance of being selected. No, because all possible groups of n items do not have an equal chance of being selected.

Identify the type of sampling used (random, systematic, conveince, stratified or cluster sampling) in the situation described below: to estimate the percentage of defects in a recent manufacturing batch, a quality control manager at General Foods sleets every 18th soup can that comes off the assembly line starting with the fifth until she obtains a sample of 40 soup cans

systematic

Identify the type of sampling used (random, systematic, conveince, stratified or cluster sampling) in the situation described below: a researcher selects every 953th social security number and surveys the corresponding person

systematic sampling

Does this sampling plan result in a simple random sample in the last election 108,248 adults voted in a country. A researcher plans to conduct a survey of 1000 of those voters. After obtaining a list of those who voted, he numbers the list from 1 to 108,248, and then he uses a computer to randomly generate 1000 numbers between 1 and 108,248. his sample consists of voters corresponding to the selected numbers

the sample is a simple random sample because every sample size 1000 has the same chance of being selected

Does this sampling plan result in a simple random sample in order to test for a differences in the way that workers and non-workers purchase magazines, a research institutions polls exactly 603 adult works and 603 adult non-workers randomly selected from the adults in the United States

the sample is not a simple random sample because every sample of size 1206 does not have the same chance of being selected

Which sampling method divides the population into sections randomly selects some of those sections then chooses all the members from the selected section to study?

*Cluster* sampling involves subdividing the population and using all members from a randomly selected group of subdivisions

Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each subdivision?

*Stratified* sampling method involves subdividing the population and uses a sample of members from each subdivision of the population.

identify the type of observational study a research company uses a device to record the viewing habits of about 15,000 households and the data collected over the past 9 years will be used to determine whether the proportion of households turned to a particular sports program increased

A retrospective study

which of the following corresponds to the case when every sample of size n has the same chance of being chosen

A simple random sample of n subjects is selected in such a way that every possible sample of the same size n has the same chance of being chosen

Fill in the blank: ____________ is used when subjects are assigned to different groups through a process of random selection

Randomization Randomization is used when subjects are assigned to different groups through a process of random selection. The logic behind randomization is to use chance as a way to create two groups that are similar. Although it might seem that we should not leave anything to chance in​ experiments, randomization has been found to be an extremely effective method for assigning subjects to groups.

determine whether the description correspond to an observational study or an experiment in a study of 440 children with a particular disease, the subjects were asked to complete a survey about their diet upon arrival to. a hospital

The given description corresponds to an observational study.

Does this sampling plan result in a simple random sample according to a game show, names of potential contestants are selected from a variety fo different sources. Names from the list are randomly selected in a way that is equivalent to writing the names of slips of paper, mixing them in a bowl, and selecting the required number of potential contestants

The sample is a simple random sample because every sample of the same size has the same chance of being selected.

A quality control engineer selects every 9000th chocolate that is produced does this sampling plan result in a simple random sample

The sample is not a simple random sample because every sample of the same size does not have the same chance of being selected.

Identify the type of sampling used (random, systematic, conveince, stratified or cluster sampling) in the situation described below: a women experienced a tax audit. The tax department claimed that the woman was audited because everyone in five randomly selected districts was being audited

cluster

Identify the type of sampling used (random, systematic, conveince, stratified or cluster sampling) in the situation described below: to determine customer opinons of their safety features, Toyota randomly selects 50 dealerships during a certain week and surveys all customers visiting the dealerships

cluster

Identify the type of sampling used (random, systematic, conveince, stratified or cluster sampling) in the situation described below: A women is selected by a marketing company to participate in a paid focus group. The company says that the woman was selected because everyone ​in ​ six randomly selected towns was being selected​

cluster sampling

Identify the type of sampling used (random, systematic, conveince, stratified or cluster sampling) in the situation described below: An internet site asks its members to call in their opinion regarding their reluctance to provide credit information online

convenience