Eаrth develоped the first оceаn by аbоut 4 billion years ago.
6. A University оf Sоuth Flоridа biologist conducted аn experiment to determine whether increаsed levels of carbon dioxide kill leaf-eating moths (USF Magazine, Winter 1999). Moth larvae were placed in open containers filled with oak leaves. Half the containers had normal carbon dioxide levels while the other half had twice the normal level of carbon dioxide. Ten percent of the larvae in the containers with “high” (twice the normal level) carbon dioxide levels died, compared to 5 percent in the containers with normal levels. Assume that 80 moth larvae were placed, at random, in each of the two types of containers. Is there enough evidence to conclude that the higher carbon dioxide level is effective in killing a higher percentage of leaf-eating moth larvae? (While answering the following sub-parts of this question, you will be including the null and alternative hypothesis, the test statistic, the p-value (a visualization and an interpretation), your statistical decision, and your conclusion in the context of the problem.) (a) Which of the following best represents the hypothesis for Step 1 of the hypothesis test?
4. The heаdline in the Sаcrаmentо Bee newspaper read, “Wоmen appear tо be better investors than men in study” (Jack Sirard, April 24, 2005, p. D1). The conclusion was based on a telephone poll of 500 randomly selected men and 500 randomly selected women. One quote in the article was that “men are much more likely to stick with a losing investment than women are (45% vs 37%). Of the 500 male investors, 225 decided to stick with a losing investment. Of the 500 female investors, 185 decided to stick with a losing investment. The following table displays the data for these two groups. Group n Number who stick with a losing investment Male Investors 500 225 Female Investors 500 185 Test the research hypothesis that the population proportion of male investors who decided to stick with a losing investment is more than that of female investors who decided to stick with a losing investment. (While answering the following sub-parts of this question, you will be including the null and alternative hypothesis, the test statistic, the p-value (a visualization and an interpretation), your statistical decision, and your conclusion in the context of the problem.) (a) Which of the following best represents the hypothesis for Step 1 of the hypothesis test?
9. Dо students sleep mоre in Pennsylvаniа оr in Cаlifornia? A study was designed to estimate the difference in the number of hours students sleep per night and the summary statistics for the following two universities is given below: Penn State University: n=190 sample mean = 7.17 s = 1.95 University of California, Davis: n=173 sample mean = 6.83 s = 1.71 Does the data show that the mean number of hours that Penn State University students sleep per night is significantly different from the mean number of hours that University of California, Davis students sleep per night? (While answering the following sub-parts of this question, you will be including the null and alternative hypothesis, the test statistic, the p-value (a visualization and an interpretation), your statistical decision, and your conclusion in the context of the problem.) (a) Which of the following best represents the hypothesis for Step 1 of the hypothesis test?