Allergic reactions to poison ivy can be miserable. Plant oils cause the reaction. Researchers at Allergy Institute did a study to determine the effects of washing the oil off within 5minutes of exposure. A random sample of 1000 people with known allergies to poison ivy participated in the study. Oil from the poison ivy plant was rubbed on a patch of skin. For500 of the subjects, it was washed off within 5 minutes. For the other 500 subjects, the oil was washed off after 5 minutes. The results are summarized in the following table.ReactionNoneMildStrongColumn TotalWithin 5 Minutes After 5 Minutes39165445006634193500Row Total4574061371000Let's use the following notation for the various events: W= washing oil off within 5 minutes, A = washing oil off after 5 minutes, N = no reaction, M = mild reaction, S = strongreaction. Find the following probabilities for a person selected at random from this sample of 1000 subjects. (Use 3 decimal places.) (c) P(NA)P(SIA)

W = within 5 minute A = after 5 minute total N =no reaction 391 66 457 M = mild reaction 65…

Answered: Allergic reactions to poison ivy can be…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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Researchers investigate how the presence of cell phones influence the quality of human interaction. Subjects are randomly selected from a population and divided into an experimental group that is asked to leave their phones in the front of the room and a control group that are not asked to leave their cell phones at the front of the room. Subjects are left alone for 10 minutes and then asked to take a survey designed to measure quality of interactions they had with others in the experiment. What statistical test is appropriate?
Businesses know that customers often respond to background music. Do they also respond to odors? One study of this question took place in a small pizza restaurant in France on two Saturday evenings in May. On one of these evenings, a relaxing lavender odor was spread through the restaurant. On the other evening no scent was used. The data gives the time, in minutes, that two samples of 30 customers spent in the restaurant and the amount they spent in euros. No odor Lavender Minutes Euros spent Minutes Euros spent 103103 15.915.9 9292 21.921.9 6868 18.518.5 126126 18.518.5 7979 15.915.9 114114 22.322.3 106106 18.518.5 106106 21.921.9 7272 18.518.5 8989 18.518.5 121121 21.921.9 137137 24.924.9 9292 15.915.9 9393 18.518.5 8484 15.915.9 7676 22.522.5 7272 15.915.9 9898 21.521.5 9292 15.915.9 108108 21.921.9 8585 15.915.9 124124 21.521.5 6969 18.518.5 105105 18.518.5 7373 18.518.5 129129 25.525.5 8787 18.518.5 103103 18.518.5 109109 20.520.5 107107…
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.
You are a medical researcher that wants to determine if your new drug can lower people's blood pressure. You recruit 60 participants with high blood pressure to be part of your study. You randomly assign participants to one of three groups to receive either 10 mg of your drug, 5 mg, or 0 mg (given as a placebo control). After 2 weeks, participants' blood pressure is measured and you compare among the 3 groups. Which statistical test would be best to determine if there is a significant difference in blood pressure among the three groups?
Peter Boag, studied the inheritance of beak depth in Galapagos finches by looking at the relationship between parent beak depth (in mm) and that of their offspring. He collected two sets of parent offspring data, once in 1976 and again in 1978. For both years he followed birds to determine which pairs belonged to which nests. Most of the parents had been previously captured so their beak depths were known. He then captured the offspring when they fledged and measured their beak depth. He calculated the "midparent" beak depth (the average beak depth of the two parents) and then compared that to beak depth of their offspring. Use regression analysis to estimate heritability for the trait beak depth from the Galapagos finches data in the above table.
Scientists are interested in the placebo effect on adults with arthritis. They randomly choose 15 adults with arthritis and give them 2 treatments: effective drug and placebo for 1 week at different times. At the end of each week, the scientists ask the participants to rate their arthritic pain level on a scale of 1-5, where 1 is little pain and 5 is a lot of pain. The researchers then take the difference of their pain levels (affective drug - placebo). The data are below. 0, 1, 2, 2, 0, -1, 3, 1, 2, -1, 0, 1, -2, -1, -6 (a) Find the 5-number summary for the difference of arthritic pain levels. Minimum = Q₁ = Median = USE SALT Q3 = Maximum = (b) One of the conditions for inference for population mean difference of paired data is normality. Outliers within a data set cast a shadow of doubt upon the normality of the population distribution. Use the 5-number summary calculated in part (a) to determine if there are any outliers in the data set. Which of the values, if any, is an outlier…
Some commercial airplanes recirculate approximately 50% of the cabin air in order to increase fuel efficiency. The researchers studied 1100 airline passengers, among which some traveled on airplanes that recirculated air and others traveled on planes that did not recirculate air. Of the 515 passengers who flew on planes that did not recirculate air, 108 reported post-flight respiratory symptoms, while 112 of the 585 passengers on planes that did recirculate air reported such symptoms. Is there sufficient evidence to conclude that the proportion of passengers with post-flight respiratory symptoms differs for planes that do and do not recirculate air? Test the appropriate hypotheses using ? = 0.05. You may assume that it is reasonable to regard these two samples as being independently selected and as representative of the two populations of interest. (Use a statistical computer package to calculate the P-value. Use pdo not recirculate − pdo recirculate. Round your test statistic to two…
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 4 Robot 1 128 138 134 125 135 Robot 2 143 134 142 147 | Ho: M₁ = 1₂ = 13 = 14 H₂: M₁ # M₂ # Hz # H4 124 4ܐ = 3ܬܐ = 2ܬܐ = 1ܐ :Ha Robot 3 132 142 | Ho: M₁ # M₂ # M3 # H4 H₂: M₁ = 1₂ = 13 = 14 138 135 128 ⒸH₁: M₁ = H₂ = 143 = 14 H: Not all the population means are equal. 151 142 At the α = 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 hypotheses. O Ho: Not all the population means are equal. 136…
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You are concerned that nausea may be a side effect of Tamiflu, but you cannot just give Tamiflu to patients with the flu and say that nausea is a side effect if people become nauseous. This is because nausea is common for people who have the flu. From past studies you know that about 30% of people who get the flu experience nausea. You collected data on 1744 patients who were taking Tamiflu to relieve symtoms of the flu, and found that 572 experienced nausea. Use a 0.01 significance level to test the claim that the percentage of people who take Tamiflu for the relief of flu symtoms and experience nausea is greater than 30%.a) Identify the null and alternative hypotheses?�0: �1: b) What type of hypothesis test should you conduct (left-, right-, or two-tailed)? left-tailed right-tailed two-tailed c) Identify the appropriate significance level.d) Calculate your test statistic. Write the result below, and be sure to round your final answer to two decimal…
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