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Fatal Traffic Accidents According to the National Highway and Traffic Safety Administration, the proportion of fatal traffic accidents in the United States in which the driver had a positive blood alcohol concentration (BAC) is 0.36. Suppose a random sample of 105 traffic fatalities in the state of Hawaii results in 51 that involved a positive BAC. Does the sample evidence suggest that Hawaii has a higher proportion of traffic fatalities involving a positive BAC than the United States at the α = 0.05 level of significance?
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- A study of color in tiger beetles is conducted to support the contention that the proportion of black beetles may vary from locality to locality (alpha=0.05). A sample of 500 beetles caught in one season near Providence, Rhode Island, yielded 95 black beetles. A catch of 112 beetles from Aqueduct, New York, contained 17 black individuals. 1. What is null and alternative hypothesis? 2. What proportions did you observe in the two localities? 3. What is the null standard error for the difference? 4. Calculate the appropriate test statistic. 5. What p-value do you associate with that statistic? 6. What do you conclude about the proportion of black beetles in the two locations?arrow_forwardStudies have shown that omega-3 fatty acids have a wide variety of health benefits. Omega-3 oils can be found in foods such as fish, walnuts, and flaxseed. A company selling milled flaxseed advertises that one tablespoon of the product contains, on average, at least 3800 mg of ALNA, the primary omega-3. a) The company plans to conduct a test to ensure that there is sufficient evidence that its claimiscorrect. Tobesafe,thecompanywantstomakesurethatevidenceshowsthe average is higher than 3800 mg. What are the null and alternative hypotheses? b) Suppose, instead, that a consumer organization plans to conduct a test to see if there is evidence against the claim that the product contains an average of 3800 mg per tablespoon. The consumer organization will only take action if it finds evidence that the claim made by the company is false and that the actual average amount of omega-3 is less than 3800 mg. What are the null and alternative hypotheses?arrow_forwardA study on the effects of color on easing test anxiety compared anxiety test scores of participants who completed a test printed on either soft yellow paper or harsh green paper. The scores for the 10 participants who completed the yellow and the 10 participants who completed it on the green paper are below (Table 5). Using an alpha level of .05, do participants who use the yellow paper report lower test anxiety than those who wrote it on the harsh green paper? Table 5. Anxiety scoresarrow_forward
- Increasing numbers of businesses are offering child-care benefits for their workers. However, one union claims that more than 80% of firms in the manufacturing sector still do not offer any childcare benefits to their workers. A random sample of 360 manufacturing firms is selected and asked if they offer child-care benefits where 300 stated that they do NOT offer child-care benefits. At an alpha level of 0.01, test the claim.arrow_forwardBenzene is a pollutant that, according to studies, can be associated with health problems. Benzene is found in air, water, and soil and comes from both industrial and natural sources. Benzene levels in indoor air are generally higher than outdoors. The main source of benzene in indoor air appears to be tobacco smoke, thus the combustion of tobacco is a major source of pollution. Benzene levels are measured in a random sample of 36 bars in a city, obtaining an average benzene level of 19.2 mg / m3, with a standard deviation of 2.1 mg / m3. Estimate the mean benzene level in bars in this city using a 95% confidence interval. (do your calculations to 4 decimal places) (need the process can be by hand ,Excel or R.) a)Other solution b)[18.48946, 19.91054] c)[19.0950, 19.3050] d)[18.5140, 19.8859] e)[18.6243, 19.7757] f)[18.4315, 19.7936]arrow_forward31% of all pygmy softshell tortoises have stripes on their shells. A herpetologist in Cititon collects a sample of 28 pygmy softshell tortoises and finds that 8 of them have stripes on their shells. Is there enough evidence to conclude, at a significance of alpha = 0.05, that the proportion of pygmy softshell tortoises in Cititon with stripes on their shells is less than 31%? What is the claim? What is the null hypothesis? What is the alternative hypothesis? What is the test statistic? What is/are the critical value(s)? Do we reject the null hypothesis? What conclusion do we draw? What is the P-value for the problem above?arrow_forward
- Peanut Allergies. In the article “Food Allergy Advice May Be Peanuts” (Science News, Vol. 174, No. 12, pp. 8–9), N. Seppa reports that early exposure to peanuts seems to lessen the risk of nut allergy. Of 4000 Jewish children sampled in Britain, 1.85% had peanut allergies; and of 4600 Jewish children sampled in Israel, where early peanut consumption is more common, 0.17% had peanut allergies. The researcher chose Jewish children in both countries to limit genetic differences between groups. a. Is this study descriptive or inferential? b. Is this study observational or experimental?arrow_forwardA nationwide study of undergraduate students reported that the mean number of drinks consumed per week during the spring semester is 7.96. The mean number of drinks consumed per week at USC is 7.64 (s.d.=2.55, N=412 Health services is concerned that USC students are consuming significantly more alcohol per week than the national average. Using an alpha level of .05, Is there sufficient evidence to be concerned? Be sure to select the correct critical value for the alternative hypothesis, and then use this evidence to make your conclusionarrow_forwardRecent incidents of food contamination have caused great concern among consumers. The article “How Safe Is That Chicken?” (Consumer Reports, Jan. 2010: 19–23) reported that 35 of 80 randomly selected Perdue brand broilers tested positively for either campylobacter or salmonella (or both), the leading bacterial causes of food-borne disease, whereas 66 of 80 Tyson brand broilers tested positive. If the true proportions of non-contaminated chickens for the Perdue and Tyson brands are .50 and .25, respectively, how likely is it that the null hypothesis of equal proportions will be rejected when a .01 significance level is used and the sample sizes are both 80?arrow_forward
- In a test of H0: p = 0.8 against H1: p ≠ 0.8, a sample of size 1000 produces Z = 2.05 for the value of the test statistic. Thus the p-value (or observed level of significance) of the test is approximately equal to:arrow_forwardLet p1 and p2 be the respective proportions of women with iron-deficiency anemia in each of two developing countries. A random sample of 1900 women from the first country yielded 513 women with iron-deficiency anemia, and an independently chosen, random sample of 1700 women from the second country yielded 515 women with iron-deficiency anemia. Can we conclude, at the 0.10 level of significance, that the proportion of women with anemia in the first country is less than the proportion of women with anemia in the second country? Perform a one-tailed test. Then complete the parts below.Carry your intermediate computations to three or more decimal places and round your answers as specified in the parts below. a. State the null hypothesis H0 and the alternative hypothesis H1. b. Find the values of the test statistic. c. FInd the p-value. d. Can we conclude that the proportion of women with anemia in the first country is less than the proportion of women with anemia in the second country?arrow_forwardA major credit card company is interested in the proportion of individuals who use a competitor’s credit card. Their null hypothesis is H0: p=0.65H0: p=0.65, and based on a sample they find a sample proportion of 0.70 and a pp-value of 0.053. Is there convincing statistical evidence at the 0.05 level of significance that the true proportion of individuals who use the competitor’s card is actually greater than 0.65 ?arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill