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 μ = 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 31 patients with arthritis took the drug for 3 months. Blood tests showed that x = 8.5 with sample standard deviation s = 2.5. 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: μ ≠ 7.4; H1: μ = 7.4 H0: μ > 7.4; H1: μ = 7.4     H0: μ = 7.4; H1: μ > 7.4 H0: μ = 7.4; H1: μ ≠ 7.4 H0: μ = 7.4; H1: μ < 7.4 (b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. The Student's t, since the sample size is large and σ is known. The Student's t, since the sample size is large and σ is unknown.     The standard normal, since the sample size is large and σ is known. The standard normal, since the sample size is large and σ is unknown. What is the value of the sample test statistic? (Round your answer to three decimal places.)(c) Estimate the P-value. P-value > 0.250 0.100 < P-value < 0.250     0.050 < P-value < 0.100 0.010 < P-value < 0.050 P-value < 0.010   Sketch the sampling distribution and show the area corresponding to the P-value.

A water company wants to analyze the the level of a particular contaminant in a water supply. The contaminant level is to be checked at several locations. Assume that the observed contaminant level is normally distributed and that each observation is independent of the others. A scientist measures the contaminant level at 10 different locations in the water supply and finds the mean level of the substance is T = 120 parts per billion (ppb) with standard deviation s = 25 ppb. Estimate the true mean contaminant level in the water supply with a 99% upper confidence bound. Answer requires 2 decimal places accuracy.

Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 50 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that ? = 7.20 ml/kg for the distribution of blood plasma. I need help with part B and D

Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma.+ Over a period of months, an adult male patient has taken eleven blood tests for uric acid. The mean concentration was x = 5.29 mg/dl. The distribution of uric acid in healthy adult males can be assumed to be normal, with o = 1.87 mg/dl. (a) Find a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. What is the margin of error? (Round your answers to two decimal places.) lower limit upper limit margin of error (b) What conditions are necessary for your calculations? (Select all that apply.) o is known o is unknown normal distribution of uric acid O uniform distribution of uric acid On is large (c) Interpret your results in the context of this problem. O We are 5% confident that the true uric acid level for this patient falls within this interval. O We are 95% confident that the…