The IQ scores for a random sample of subjects with medium lead levels in their blood and another random sample of subjects with high lead levels in their blood are given below. Use a 0.05 significance level to test the claim that subjects with medium lead levels have full IQ scores with a higher median that the median full IQ score for subjects with high lead levels. Does lead level appear to affect full IQ scores? Click the icon to view the data table. First define the null and alternative hypotheses. Ho: H₁: Data Table - X

In the 1980's it was believed that congenital abnormalities affected about 5.4% of the nation's children. Some people believe that an increase in the chemicals in the environment has led to an increase in the number of abnormalities. A recent study examined 400 randomly selected children and found that 29 of them showed signs of an abnormality. Does this provide evidence that the risk of congenital abnormalities has increase? Use a 0.05 to make your decision. What is the resulting test statistics?

A psychological study wants to analyze the relationship between anxiety and binge drinking; a questionnaire for anxiety and questionnaire for binge drinking is administered to each subject. What would be a good statistical test to test the hypothesis?

If you wanted to determine whether mean levels of blood glucose were different according to gender and age a one-way ANOVA would be an appropriate test to perform.  True  False

Use the following information to answer the question. Many couples believe that it is getting too expensive to host an "average" wedding in the United States. According to the website www.costofwedding.com,theaveragecostofaweddingintheU.S.in 2009 was $24,066. Recently, in a random sample of 40 weddings in the U.S. it was found that the average cost of a wedding was $23,224, with a standard deviation of $2,903. On the basis of this, a 9 5% confidence interval for the mean cost of weddings in the U.S. is $22,296 to $24,152. Does the confidence interval provide evidence that the mean cost of a wedding has decreased? Explain your reasoning.

The College Board provided comparisons of Scholastic Aptitude Test (SAT) scores based on the highest level of education attained by the test taker's parents. A research hypothesis was that students whose parents had attained a higher level of education would on average score higher on the SAT. The overall mean SAT math score was 514. SAT math scores for independent samples of students follow. The first sample shows the SAT math test scores for students whose parents are college graduates with a bachelor's degree. The second sample shows the SAT math test scores for students whose parents are high school graduates but do not have a college degree. College Grads 485 487 518 517 650 542 570 426 566 499 588 562 497 448 592 453   High School Grads 442 492 580 478 479 425 486 485 528 390 524 535 (b) What is the point estimate of the difference between the means for the two populations?   (c) Find the value of the test statistic. (Round your answer…

Twelve inmates in a particular prison took part in an anger management class. Before it began, the median score on an anger control assessment of the group was 42 (out of a maximum of 60). After the six month class, the participants scores on the same assessment were 35, 41, 40, 44, 57, 36, 39, 47, 58, 39, 42, 39.   1. Construct a boxplot of the data and explain briefly why a sign test is appropriate to use in this case

A consumer research group purchased identical items in eight drugstores. The mean cost for the purchased items was $113.49. The mode was $112. Using the empirical relationship among mean, median, and mode, estimate the median and comment on the skewness of the distribution.

One study found a negative correlation between participant’s age and hours of sleep they got (as they got older, they slept less). Which additional fact would lead you to believe that the relationship between age and hours of sleep is one of causation and not correlation?     Jim is 63 and sleeps more than he did when he 47.     Josie is 40 and sleeps fewer hours than when she was 30.     The participants were randomly selected, the sample size was large, and the participants did not know the goal of the study.     Jennie sometimes has difficulty sleeping.

A researcher gathered a sample of participants who volunteered for a studying of phobias. She measured anxiety level of participants as they viewed photos of spiders and again when they viewed puppies. Which statistical test is appropriate for this study and why?