Let x be a random variable that represents the pH of arterial plasma (i.e., acidity of the blood). For healthy adults, the mean of the x distribution is ? = 7.4.† A new drug for arthritis has been developed. However, it is thought that this drug may change blood pH. A random sample of 36 patients with arthritis took the drug for 3 months. Blood tests showed that x = 8.8 with sample standard deviation s = 3.4. Use a 5% level of significance to test the claim that the drug has changed (either way) the mean pH level of the blood. (a) What is the level of significance? State the null and alternate hypotheses. H0: ? = 7.4; H1: ? < 7.4H0: ? > 7.4; H1: ? = 7.4    H0: ? ≠ 7.4; H1: ? = 7.4H0: ? = 7.4; H1: ? > 7.4H0: ? = 7.4; H1: ? ≠ 7.4 (b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. The standard normal, since the sample size is large and ? is unknown.The standard normal, since the sample size is large and ? is known.    The Student's t, since the sample size is large and ? is unknown.The Student's t, since the sample size is large and ? is known. What is the value of the sample test statistic? (Round your answer to three decimal places.) (c) Find the P-value. (Round your answer to four decimal places.) Sketch the sampling distribution and show the area corresponding to the P-value.         (d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level ?? At the ? = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant.At the ? = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant.    At the ? = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant.At the ? = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant. (e) Interpret your conclusion in the context of the application. There is sufficient evidence at the 0.05 level to conclude that the drug has changed the mean pH level of the blood.There is insufficient evidence at the 0.05 level to conclude that the drug has changed the mean pH level of the blood

The scores on a test are normally distributed with a mean of 150 and a standard deviation of 30. Find the score that is 2 1/2 standard deviations above the mean.

When engaging in weight-control (fitness/fat burning) types of exercise, a person is expected to attain approximately 60% of his or her maximum heart rate. For 20-year-olds, this rate is approximately 120 bpm. A simple random sample of one hundred 20-year-olds was taken, and the sample mean was found to be 107 bpm, with a standard deviation of 45 bpm. Researchers wonder if this is evidence to conclude that the expected level is actually lower than 120 bpm. To determine this, we test the following hypotheses: Ho: H= 120 versus H₂ μ< 120 Suppose the mean and standard deviation obtained were based on a sample of size 25 rather than 100.

On an exam with u=52, a person has a score of x=14, which value for the standard deviation would give this person the highest position in the class distribution?

Do wearable devices that monitor diet and physical activity help people lose weight? Researchers had 237 subjects who were already involved in a program of diet and exercise use wearable technology for 24 months. They measured their weight (in kilograms) before using the technology and 24 months after using the technology. The 237 differences in weight (weight after 24 months minus weight before using the wearable technology) had ?⎯⎯⎯=−3.5�¯and ?=7.8.. Let ?� be the mean weight difference.     What is the test statistic? Give your answer to three decimal places. ?= Identify the correct interpretation of the results based on your analysis.Which is the correct answer ? There is very convincing evidence that there is a decrease in average weight after wearing the device. There is a small amount of evidence that there is a decrease in average weight after wearing the device. There is very convincing evidence that there is an increase in average weight…

You have developed an exam to measure knowledge of biology and administered it to a large number of people. On this exam, u= 85 and o = 10. You standardize the distribution so that the new mean and standard deviation are u = 50 and o = 5 If someone takes the exam and receives a score of 73 (before the score is transformed), what will this score be once it is transformed for the new (standardized) distribution?

 Suppose that in the population of all healthy humans, body temperature follows a normal distribution with mean 98.2 and standard deviation of 0.5. Suppose a random sample of 20 healthy humans is taken. Which sample mean body temperature would be higher than 40% of all sample me and Body temperatures?

It takes an average of 12.8 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will change if the patient is immediately told the truth about the injury. The EMT randomly selected 51 injured patients to immediately tell the truth about the injury and noticed that they averaged 14.1 minutes for their blood to begin clotting after their injury. Their standard deviation was 4.48 minutes. What can be concluded at the the a = 0.01 level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: ? v Select an answer V Hj: ? v Select an answer V c. The test statistic ? v = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ? va f. Based on this, we should Select an answer v the null hypothesis. g. Thus, the final conclusion is that ... O The data suggest the populaton mean is significantly different from 12.8 at a =…

High density lipoprotein (HDL) in healthy males follows a normal distribution with a mean of 50 and a standard deviation of 8. What proportion of healthy males has HDL exceeding 60?

It takes an average of 10.2 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will decline if the patient is immediately told the truth about the injury. The EMT randomly selected 60 injured patients to immediately tell the truth about the injury and noticed that they averaged 10.1 minutes for their blood to begin clotting after their injury. Their standard deviation was 1.62 minutes. What can be concluded at the the a = 0.01 level of significance? a. For this study, we should use Select an answer b. The null and altemative hypotheses would be: Họ: Select an answer H1: ? Select an answer c. The test statistic (please show your answer to 3 decimal places.) d. The p-value = e. The p-value is (? va f. Based on this, we should Select an answer v the null hypothesis. g. Thus, the final conclusion is that .. (Please show your answer to 4 decimal places.) O The data suggest the population mean is not significantly less than 10.2 at a = 0.01, so there is…