Question

Assignment #11 Single Sample t-Test What factor determines whether you should use a z-test or a t-test statistic for a hypothesis test? 11.1 A sample is selected from a population mean of u 30. A treatment is administered to the individuals in the sample and, after treatment, the sample mean found to be M 11.2 = 31.3 with a sample variance of s2 9 If the sample consists of n 16 individuals, are the data sufficient to conclude that there is a significant treatment effect using a two-tailed test with a = ,05? are the data sufficient to conclude a If the sample consists of n 36 individuals, that there is a significant treatment effect using a two-tailed test with a=.05? Ackerman & Goldsmith (2011) found that students who studied text from printed 11.3 hard copy had better test scores than students who studied text presented on a screen. In a related study, a professor noticed that several students in a large class had purchased the e-book version of the course textbook. For the final exam, the overall average for the entire class was u= 81.7, but then=9 students who purchased the e-book had a mean of M 77.2 with a standard deviation of s = 5.7. Do these data indicate a significant decrease in test scores on the final exam due to the use of a e-book? Use a one-tailed test with a .05. Oishi & Shigehiro (2010) report that people who move from home to home frequently as children tend to have lower than average levels of well-being To further examine this relationship, a psychologist obtains a sample of n 12 young adults who each experienced 5 or more different homes before they were 16 years old. These participants were given a standardized well-being questionnaire for which the general population has an average score of u 40. The well-being scores for this sample are as follows: 38. 37, 41, 35, 42, 40, 33, 33, 36, 38, 32, 39. On the basis of this sample, is well-being for frequent the well-being of the general population? Test with alpha or two-tailed test? 11.4 as adults. movers significantly different from .05. Is this a one a Note for problems 11.2-11.4 above: Be sure and show a full diagram of the research design. Also show all steps and calculations you made for each test following the process outlined in the t-test formula sheet handout. What statistical decision do you make in each case? Finally repor our results professionally in APA format (see last step of the formula sheet for this module).

this is a single sample t test problem

this is math

Answer 1

8

Normally, you use the t-table when the sample size is small (sample size is less than 30) and the population standard deviation σ is unknown.

Use Z distribution when population standard deviation is known.

Z-scores are based on your knowledge about the population’s standard deviation and mean. T-scores are used when the conversion is made without knowledge of the population standard deviation and mean.

Answer 2

Openness of vocabulary implies both free admission of words from other languages and the ready creation of compounds and derivatives. English adopts (without change) or adapts (with slight change) any word really needed to name some new object or to denote some new process. Words from more than 350 languages have entered English in this way. Like French, Spanish, and Russian, English frequently forms scientific terms from Classical Greek word elements. Although a Germanic language in its sounds and grammar, the bulk of English vocabulary is in fact Romance or Classical in origin.