It has been found that 1 in 12 inpatients is exposed to MRSA, an infectious bacterial species that is resistant to treatment with antibiotics. Out of a sample of 60 patients, how many do you expect have been exposed to this bacteria?

In a study conducted at Virginia Tech, the plasma ascorbic acid levels of pregnant women were compared for smokers versus nonsmokers. Thirty women in the last three months of pregnancy, free of major health disorders and ranging in age from 15 to 32 years, were selected for the study. Prior to the collection of 20 ml of blood, the participants were told to avoid breakfast, forgo their vitamin supplements, and avoid foods high in ascorbic acid content. From the blood samples, the accompanying plasma ascorbic acid values were determined, in milligrams per 100 milliliters. Is there sufficient evidence to conclude that there is a difference between plasma ascorbic acid levels of smokers and nonsmokers? Assume that the two sets of data came from normal populations with unequal variances. Use a P-value. Click the icon to view the plasma ascorbic acid values. Let sample 1 be the nonsmokers and let sample 2 be the smokers. State the null and alternative hypotheses. Hoi Hi-H2 = 0 (Type integers…

Suppose that 73.2% of all adults with type 2 diabetes also suffer from hypertension. After developing a new drug to treat type 2 diabetes, a team of researchers at a pharmaceutical company wanted to know if their drug had any impact on the incidence of hypertension for diabetics who took their drug. The researchers selected a random sample of 1000 participants who had been taking their drug as part of a recent large-scale clinical trial and found that 718 suffered from hypertension. The researchers want to use a one‑sample ?z‑test for a population proportion to see if the proportion of type 2 diabetics who have hypertension while taking their new drug, ?p, is different from the proportion of all type 2 diabetics who have hypertension. They decide to use a significance level of ?=0.01α=0.01. Determine the value of the ?z‑test statistic. Give your answer precise to two decimal places. Determine the ?-valueP-value for this test. Give your answer precise to three decimal places.

A psychologist has developed a mental alertness test. She wishes to study the effects (if any) of type of food consumed on mental alertness. Twenty-one volunteers were randomly divided into two groups. Both groups were told to eat the amount they usually eat for lunch at noon. At 2:00 P.M., all subjects were given the alertness test. Group A had a low-fat lunch with no red meat, lots of vegetables, carbohydrates, and fiber. Group B had a high-fat lunch with red meat, vegetable oils, and low fiber. The only drink for both groups was water. The test scores are shown below. Group A 67 93 82 69 76 47 43 58 92 63 52   Group B 70 57 75 59 66 49 55 46 45 91 89 72 Use a 10% level of significance to test the claim that there is no difference in mental alertness distributions based on type of lunch. (a) What is the level of significance? (b) Compute the sample test statistic. (Use 2 decimal places.) (c) Find the P-value of the sample test statistic. (Use 4 decimal places.)

Hyperhidrosis is a stressful medical condition characterized by chronic excessive sweating. Botox was approved for treatment of hyperhidrosis in adults in 2004. A clinical trial examined the effectiveness of Botox for excessive armpit sweating in teenagers aged 12 to 17 years. Participants received either a Botox injection or a placebo injection (a simple saline solution) and were examined four weeks later to see if their sweating had been reduced. Here are the study's findings: Botox Placebo Total Reduced Confidence Interval: 72 52 124 Not Reduced 28 We are 95% confident that there is hyperhidrosis who experienced a reduction in sweating. 148 176 Total 100 200 - Construct a 95% confidence interval for p₁ - P2 where p₁ denotes the proportion of teenagers who experienced a reduction in sweating in the Botox group and p2 denotes the proportion of teenagers who experienced a reduction in sweating in the placebo group. Round your answers to three decimal places, and use four decimal places…

The null hypothesis: H. :|| The alternative hypothesis: H :0 1 The type of test statistic: (Choose one) v The value of the test statistic: (Round to at least three decimal places.) The p-value: (Round to at least three decimal places.) Can we reject the researchers' claim that the mean recovery time when treated with multivitamin is less than or equal to the mean recovery time when treated with vitamin C only? Yes No

You may need to use the appropriate technology to answer this question. How long it takes paint to dry can have an impact on the production capacity of a business. An auto body & paint business invested in a paint-drying robot to speed up its process. An interesting question is, "Do all paint-drying robots have the same drying time?" To test this, suppose we sample five drying times for each of different brands of paint-drying robots. The time in minutes until the paint was dry enough for a second coat to be applied was recorded. Suppose the following data were obtained. Robot 1 129 137 135 124 140 Robot 2 143 133 142 146 131 Robot 3 Robot 4 133 O Hoi H₁ H₂ H3 #44 H₂H₁ H₂ H3 H4 142 136 137 132 O H₂H₁ = H₂ = H3 H4 H₂: Not all the population means are equal. 151 O Ho: Not all the population means are equal. H₂: H₁ = H₂ = μ3 = μ4 142 136 At the a = 0.05 level of significance, test to see whether the mean drying time is the same for each type of robot. State the null and alternative…

Do lizards play a role in spreading plant seeds? Some research carried out in South Africa would suggest so. Researchers on a study collected 400 seeds of a particular type of fig, 100 of which were from each treatment: lizard dung, bird dung, rock hyrax dung, and uneaten figs. They planted these seeds in batches of 5, and for each group of 5 they recorded how many of the seeds germinated. This resulted in 20 observations for each treatment. The treatment means and standard deviations are given in the accompanying table. Treatment Uneaten figs 20 2.50 0.29 Lizard dung 20 2.40 0.32 Bird dung 20 1.80 0.35 Hyrax dung 20 1.40 0.29 (a) Construct the appropriate ANOVA table. (Use technology. Round your answers to three decimal places.) Degrees of freedom Source of Sum of Mean F Ratio F Prob variation squares squares Between Groups Within Group Total 79 Test the hypothesis that there is no difference between mean number of seeds germinating for the four treatments. (Use a significance level…

A researcher is creating a new treatment protocol for Myelodysplastic Syndrome (MDS), a form of preleukemia.  Following the old treatment protocol, 28% of patients with MDS will develop leukemia within 5 years of MDS diagnosis.  He believes his new treatment protocol will lead to fewer MDS patients developing leukemia.  He takes a random sample of 100 individuals on his new treatment protocol.  Of these 100 individuals, 20 develop leukemia within 5 years of MDS diagnosis.   In questions 8-9, create a 98% confidence interval for the true proportion of all MDS patients on this new treatment who will develop leukemia within 5 years of MDS diagnosis. What is the confidence interval? Do not round your answer. What is the interpretation of your confidence interval?

A new screening test for Lyme disease is developed for use in the general population. The sensitivity and specificity of the new test are 60% and 70%, respectively. Five hundred people are screened at a clinic during the first year the new test is implemented. Assume the true prevalence of Lyme disease among clinic attendees is 10%. Calculate the predictive value of a positive test.