Chapter 12.5, Problem 12.80E

A magizine claimed that more than 55% of adults skip breakfast at least 3 days a week. To test this, a dietician selected a random sample of 80 adults and asked them how many days a week they skip breakfast. 45 of them responded that they skip breakfast at least 3 days a week. At a= .10, test the magazine's claim

Since muscle tension in the head region has been associated with tension headaches, a researcher reasoned that if the muscle tension could be changed, perhaps the headaches would also be changed. The researcher designed an experiment in which nine subjects with tension headaches participated. The subjects kept daily logs of the number of headaches they experienced during a 2-week baseline period. Then the researcher trained them to change their muscle tension in the head region, using a biofeedback device. For this experiment, the biofeedback device was connected to a muscle in the forehead region. The device indicated the subject's amount of tension in the muscle to which it was attached and helped them achieve low tension levels. After 6 weeks of training, during which the subjects became successful at maintaining low muscle tension, they again kept a 2-week log of the number of headaches experienced. The following are the number of headaches recorded during each 2-week period.…

Show that the estimator of Exercise 21 is consistent.

To check the activation level of data scientists, a population of data scientists was asked to play games for a fixed time duration and their brain activation levels were tested. The outcome of this research stated that playing the mobile games for a fixed time duration improved the concentration level with an average brain activation level of 100 units. If a sample of 12 data scientists were tested for the same experiment, the brain activation levels were reported as follows: 105, 90, 91, 96, 96, 91, 100, 105, 99, 107, 103 and 92 a. Does this data suggest that the population mean reading for the brain activation level under the given conditions differs from 100? State and test the appropriate hypotheses using a significance level of 0.05. b. Find the 90% confidence interval, and check whether the above given sample lies within this interval or not?

Average IQ scores for young school children are known to be 100 (SD = 15).  However, the literature indicates that children’s intelligence may be decreased if their mothers have German measles during pregnancy.  Using hospital records, a researcher obtained a sample of n = 25 school children whose mothers all had German measles during their pregnancies.  Do the data indicate that children born to mothers who had German measles during the pregnancy have significantly lower IQ scores than typical young school children?   DATA (Fictional)             child IQ scr 1 91 2 111 3 97 4 95 5 96 6 95 7 95 8 96 9 94 10 93 11 95 12 92 13 96 14 91 15 97 16 93 17 92 18 99 19 93 20 97 21 85 22 94 23 96 24 95 25 96 A. What is the population standard deviation?    B. What is the population standard error of the mean?    C.  On the frequency…

Average IQ scores for young school children are known to be 100 (SD = 15).  However, the literature indicates that children’s intelligence may be decreased if their mothers have German measles during pregnancy.  Using hospital records, a researcher obtained a sample of n = 25 school children whose mothers all had German measles during their pregnancies.  Do the data indicate that children born to mothers who had German measles during the pregnancy have significantly lower IQ scores than typical young school children?   DATA (Fictional)             child IQ scr 1 91 2 111 3 97 4 95 5 96 6 95 7 95 8 96 9 94 10 93 11 95 12 92 13 96 14 91 15 97 16 93 17 92 18 99 19 93 20 97 21 85 22 94 23 96 24 95 25 96 Looking at the research scenario for this lab, you will see that it says, “ literature indicates that children’s intelligence may…

A researcher is interested in conducting an observational study looking at the incidence of breast cancer in women 40-65 years of age followed for a period of 15 years. The researcher is interested in showing that the incidence of breast cancer has risen from 24% to 35% since the last surveillance data was published covering this population. If the researcher wants to be 95% confident with 90% power, how many participants should be enrolled?

Average IQ scores for young school children are known to be 100 (SD = 15).  However, the literature indicates that children’s intelligence may be decreased if their mothers have German measles during pregnancy.  Using hospital records, a researcher obtained a sample of n = 25 school children whose mothers all had German measles during their pregnancies.  Do the data indicate that children born to mothers who had German measles during the pregnancy have significantly lower IQ scores than typical young school children?   DATA (Fictional)             child IQ scr 1 91 2 111 3 97 4 95 5 96 6 95 7 95 8 96 9 94 10 93 11 95 12 92 13 96 14 91 15 97 16 93 17 92 18 99 19 93 20 97 21 85 22 94 23 96 24 95 25 96 Looking at the research scenario for this lab, you will see that it says, “ literature indicates that children’s intelligence may…

Average IQ scores for young school children are known to be 100 (SD = 15).  However, the literature indicates that children’s intelligence may be decreased if their mothers have German measles during pregnancy.  Using hospital records, a researcher obtained a sample of n = 25 school children whose mothers all had German measles during their pregnancies.  Do the data indicate that children born to mothers who had German measles during the pregnancy have significantly lower IQ scores than typical young school children? child IQ scr 1 91 2 111 3 97 4 95 5 96 6 95 7 95 8 96 9 94 10 93 11 95 12 92 13 96 14 91 15 97 16 93 17 92 18 99 19 93 20 97 21 85 22 94 23 96 24 95 25 96   A. Is the dependent variable categorical or quantitative? A   B. What is the mean IQ for the sample? B   C. What is the sample standard deviation? C   D. What…