Sophia Statistics Final Milestone,

Several scientific and statistical studies have been done to determine whether or not pollutants in soil increase the incidence of cancer. A study based on many previous studies summarizes that there is no link between pollutants in soil and cancer. This kind of statistical study is called a __________. Retrospective study Matched-pair design Clinical trial Prospective study RATIONALE Since the data has already been collected it is called a retrospective study design. CONCEPT Prospective and Retrospective Studies 2 A researcher has a table of data with four column variables and three row variables. The value for the degrees of freedom in order to calculate the statistic is __________. 11 6 3 12 RATIONALE Recall to get the degrees of freedom we use df = (r-1)(c-1) where c and r are the number of rows and columns. This means df = (4-1)(3-1) = 3*2 =6. CONCEPT Chi-Square Test for Association and Independence 3 Using the Venn Diagram below, what is the conditional probability of event B occurring, assuming event A has happened [P(B|A)]? 0.24 0.63 0.77 0.41 RATIONALE To get the probability of B given A has occurred, we can use the following conditional formula: The probability of A and B is the intersection, or overlap, of the Venn diagram, which is 0.41. The probability of A is all of Circle A, or 0.24 + 0.41 = 0.65. CONCEPT Conditional Probability 4 Keith tabulated the values for the average speeds on each day of his road trip as 61.5, 62.2, 55.7, 50.6, 71.3, 70.8, and 66.8 mph. He wishes to construct a 90% confidence interval. What value of t* should Keith use to construct the confidence interval? Answer choices are rounded to the thousandths place. 1.895 1.943 1.415 1.440