It undertakes a survey of local residents in Beijing (valid sample n = 271) to validate the above hypothesis.
Administer the survey to a statistically valid sample of your school population, and tabulate the results.
Nancy Brown, Athenahealth's senior vice president for clinical service development, acknowledged that "it is not a statistically valid sample".
Separated citrate plasma (plasma from a blue top tube) is the only valid sample.
Thus research, such as that unveiled by the National Centre for Social Research (NatCen) suggesting that 30% of a statistically valid sample identify as "a little" or "very" prejudiced, causes great discombobulation.
Under the Senate bill, importers would have to provide large amounts of data to the F.D.A. to show, for example, that a statistically valid sample of all drug shipments had been tested to ensure compliance with federal standards.
Mr. Russianoff said that the number of responses created a statistically valid sample, but he also said that the group "had to make some subjective judgments" about where to distribute the study.
Asking a statistically valid sample of customers "How likely is it that you would recommend our company to a friend or colleague?" enables you to calculate your net-promoter score: the ratio of promoters to detractors.
While the 620 people who responded to the late April survey may not represent a statistically valid sample, the results reflect the views of career federal employees who work at more than 50 federal agencies.
The 252 respondents, while not a scientifically valid sample and restricted to one segment of the app market, indicated what many people had suspected: the app world is an ecology weighted heavily toward a few winners.
"We asked for a valid sample," Wilson said, adding the department had asked for results from both single and dual parent families.
