Exam 16: Generalizing a Sample's Findings to its Population and Testing Hypotheses About Percents and Means

In hypothesis testing, given the standard error of the percentage (or mean)remains constant, the closer the hypothesized value is to the sample statistic:

The standard error will increase if sample size is increased.

If a researcher wishes to have a 95 percent confidence interval, he/she should use a standard error value of:

The proper command sequence in SPSS to generate a confidence interval for a percentage is:

Researchers use ________ to estimate the population parameter within a range because there is always sampling error.

Directional hypotheses contain statements of "more than" or "less than."

If we are testing the hypothesis that a population mean is equal to 50 percent, then the alternative hypothesis must be that the population mean is not equal to 50 percent.

All other variables held constant, a 95 percent confidence interval will give us a ________ range, as opposed to a 99 percent confidence interval.

Greek letters are used for sample statistics and Roman letters are used for parameters.

To calculate the mean and to generate a confidence interval estimate of the population mean, the sequence of menu commands in the SPSS for Windows is ANALYZE; COMPARE MEANS; ONE SAMPLE t TEST.

Detailed confidence intervals are typically reported to clients.

John Daniel is the brand manager for Healthy-Pick Cookies, Inc. John had been through the new product development process and has developed a new cookie that has very good taste and texture, yet has no calories, fat, sodium, or cholesterol. Concept tests on the product have been excellent and now John is ready to test market the new cookie and has selected Phoenix, Arizona, as his first test city. But before he starts the test market, John wants to conduct a research project that will help him forecast sales, so that he can better prepare production to supply the test market. The project leads to a probability sample in which household members are randomly called and are given a thorough description of the new cookie, including the price and choices of flavors. The key question respondents are asked is how likely it is that they will actually buy the new cookie, and this is measured on a 7-point intensity continuum scale ranging from 1 being Very Unlikely to 7 being Very Likely. Respondents were also asked how many boxes of cookies they would expect to buy in a month. At the end of the study, the researchers tell John that 8 percent of the households contacted stated that they were Very Likely to buy the new cookie. In order to get an estimate of the sales potential in the test market John could:

A practical use of confidence intervals is that they may be used to forecast likely, pessimistic, and optimistic forecasts.

Intuitive hypothesis testing is quite complicated and uses linear algebra to test mathematically intuitive algorithms.

The logic of hypothesis testing is that if we assume that the hypothesized value is the population parameter, then, at the 95 percent level of confidence, if we took 100 separate samples, the z value for 95 of those samples would fall between + or -1.96.

Values that are computed from a complete census and are considered precise and valid measures of the population are called:

________ is the process of using sample information to compute an interval that describes the range of a parameter such as a population mean or the population percentage.

When computing standard error, if the sample size increases, then the standard error:

Forming a directional hypothesis means that we are still seeking a direction for the hypothesis.

An important sample statistic used in making estimates about population parameters is sample size.