A certain drug can be used to reduce the acid produced by the body and heal damage to the esophagus due to acid reflux. The manufacturer of the dru claims that more than 91% of patients taking the drug are healed within 8 weeks. In clinical trials, 212 of 229 patients suffering from acid reflux disease were healed after 8 weeks. Test the manufacturer's claim at the α = 0.05 level of significance. ... Because npo (1-Po) = 0.2 > 10, the sample size is less than 5% of the population size, and the sample can be reasonably assumed to be random, the requirements for testing the hypothesis are satisfied. (Round to one decimal place as needed.)

On March 2005, a poll surveyed 535 adults aged 18 years old or older and asked “ Do you think there is life on other planets or not?. Of the 535, 326 responded yes. same question was asked on September3,2000, 385 of the 535 individuals surveyed said yes. Can you conclude that the proportion has decreased at alpha = 0.05 level of significance.

The mean blood cholesterol level for all men aged 20 to 34 years is μ=188μ=188 mg/dl. We suspect that the mean for cross-country runners is lower. We take a random sample from all cross-country runners and measure the cholesterol level of each runner. We set α=0.10α=0.10 and correctly calculate a p−valuep−value of 0.08. Suppose someone else has additional information unavailable to us and it is known that IN REALITY cross-country runners actually do have lower cholesterol levels. Based on our calculations, what conclusion did we reach and did we make an error?   The mean blood cholesterol level for all men aged 20 to 34 years is μ=188μ=188mg/dl. We suspect that the mean for cross-country runners is lower. We take a random sample from all cross-country runners and measure the cholesterol level of each runner. We set α=0.10α=0.10and correctly calculate a p−valuep−valueof 0.08. Suppose someone else has additional information unavailable to us and it is known that IN REALITY…

In a certain article, laser therapy was discussed as a useful alternative to drugs in pain management of chronically ill patients. To measure pain threshold, a machine was used that delivered low-voltage direct current to different parts of the body (wrist, neck, and back). The machine measured current in milliamperes (mA). The pretreatment experimental group in the study had an average threshold of pain (pain was first detectable) at u = 3.30 mA with standard deviation o = 1.23 mA. Assume that the distribution of threshold pain, measured in milliamperes, is symmetric and more or less mound-shaped. (Round your answers to two decimal places.) (a) Use the empirical rule to estimate a range of milliamperes centered about the mean in which about 68% of the experimental group will have a threshold of pain from mA to (b) Use the empirical rule to estimate a range of milliamperes centered about the mean in which about 95% of the experimental group will have a threshold of pain from mA to mA

A new chemotherapy drug is released to treat leukemia and researchers suspect thst the drug may have fewer side effects than the most commonly used drug to treat leukemia. The two drugs have equivalent efficacy. In order to determine if a larger study should be conducted to look into the prevalence of side effects for the two drugs, set up a Mann-Whitney U test at the alpha equals .05 level and interpret its results.  Number of reported side effects Old drug    0 1 3 3 5 New drug  0 0 1 2 4

A group of 15 first graders were asked to complete a manual dexterity test.  Six students completed it in more than 7 minutes while eight students completed it in less than 7 minutes. At α   = 0.05, test the claim that the median time for all first graders is 7 minutes. A.  What is the test statistic?   B.  What is the critical value?

A nationwide survey in 2001 revealed that U.S. grade-school children spend an average of µ = 8.0 hours per week doing homework. The distribution is normal with σ = 2.5. Last year, a sample of n = 100 grade-school children was given the same survey.  For this sample, the mean number of homework hours was 7.4.   Has there been a significant change in the homework habits of grade-school children?  Test with α = .05. For each problem students will write out all steps of hypothesis testing: State the null and research hypotheses. Set the level of risk associated with the null hypothesis. Select the appropriate test statistic. Compute the test statistic value (called the obtained value). Determine the value needed for rejection of the null hypothesis using the appropriate table of critical values for the particular statistic. Compare the obtained value and the critical value. Make your decision

A randomized trial assessed the efficacy of colchicine (an anti-inflammatory drug) in reducing recurrence of pericarditis (inflammation of the outer layer of the heart). The study randomized 42 patients to colchicine and 49 patients to standard therapy, and followed them all for 6 months. They reported the following results: Colchicine Standard Rx 0-15% 35-50% 60-75% Developed Recurrent Pericarditis Yes No 10 32 27 In what range is the relative risk reduction? 85-100% 22 32 59 42 49 91 The relative risk reduction can not be calculated from these data

A group of 15 first graders were asked to complete a manual dexterity test.  Six students completed it in more than 7 minutes while eight students completed it in less than 7 minutes.   At αα   = 0.05, test the claim that the median time for all first graders is 7 minutes. A.  What is the test statistic?   B.  What is the critical value?