Definitions
No attempt is made to control the characteristics of the experimental units sampled.
What is an observational study?
Experimental conditions (manipulated by the researcher).
What is a treatment?
X = the number of calories within a randomly selected serving of tofurkey from the population
What is the Normal random variable?
μ = true/pop mean length of time to complete STA 261 final exam
What is my parameter?
Random sampling technique (or good sampling techniques) and sufficiently large sample size.
What are the conditions for inference for One Population Proportion and One Population Mean?
Pharmacists in Ontario are classified into the following categories: Community, Hospital, or Academic. 20 Pharmacist from each category are randomly selected and surveyed about this year's flu vaccine supply.
What is stratified sampling method?
Response variable being measured
What do researchers compare across treatments?
P(X<480)
What is 0.4734?
In a random sample of 500 Miami University freshmen, 150 of them indicated that they bought a car to campus. A 95% confidence interval for the proportion of Miami University freshmen that brought a car to campus is (0.2598, 0.3402). Report the value of point estimate.
What is p̂ = 150/500 = 0.3?
When writing a conclusion to a hypothesis test you either reject or fail to reject the null
What is a decision made by comparing p-value to significance level?
A local hair dresser would like feedback on her work. She sends an email survey to all of her customers and asks them to fill it out.
What is non-response bias?
Neither the volunteers nor the data collector know which injection the volunteer received.
What is double-blinding?
The sample size is large enough (n=500). The data were collected using random sampling. Now, we can use the normal distribution to find the probabilities/percentiles associated with this sampling distribution.
What is the CLT?
In a random sample of 500 Miami University freshmen, 150 of them indicated that they brought a car to campus. A 95% confidence interval for the proportion of Miami University freshmen that brought a car to campus is (0.2598, 0.3402). Report the MOE
What is 0.0402?
Reject a true null (i.e. rejecting when you should not)
What is a Type I Error?
The sample mean can only be used with quantitative data and the sample proportion can only be used with categorical data.
What is the difference between sample proportions and sample means?
Sixty college students were recruited to participate in a study and half were assigned to either Group A or Group B.
What is replication?
Approximately Normal
What is the sampling distribution of the sampling mean?
We are 95% confident that the true proportion of Miami University freshmen that brought a car to campus is between 0.2598 and 0.3402.
What is the interval estimate in context?
Fail to reject a false null (i.e. not rejecting when you should)
What is a Type II Error?
The population observations represent a randomly selected person from the population and sampling distribution represents the entire sample size (census).
What is the difference between an observation from the population and an observation from the sampling distribution?
Half of the volunteers were randomly assigned to receive the new vaccine. While the other half of the volunteers received saline. Neither the volunteers nor the data collectors know which injection the volunteers received.
What is control (placebo & double-blinding)?
P(X<480)
What is 0.0680?
The quantity that we add and subtract to our point estimate to obtain our interval estimate. The MOE is always equal to half the width of the interval.
What is margin of error?
Displays the entire set of plausible values for the population parameter.
What is a confidence interval?