Question

Let x be a random variable that represents the pH of arterial plasma (le, acidity of the wood). For healthy adults, the mean of the x distribution 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 41 patients with arthritis took the drug for 3 months. Blood tests showed that - 8.5 with sample standard deviations - 31. Use a % 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 cance? State the null and a ternate hypotheses Moi - 7AMM> 7.4 - Ng' 4 - 74, P A + A. Mou > 7.4; M = 7.4 74 7.4 MO! 7.4; 1 74 (b) What samping distribution will you use? Explain the rationale for your choice of aming der The standard normal, since the sample size is large and is known The Student'st, since the samplestre is large and is known The students, since the sample size is large and is unknown The standard normal, since the sample size is large and is unknown pe What is the value of the sample test statistic (Round your answer to three decals ) (c) Estimate the value. op value 0.250 0.100 < P-value < 0.250 -0.050 < valve < 0.100 0.010 < < 0.050 Palue <0.010 Sketch the samping distribution and show the area corresponding Sketch the sampling distribution and show the area corresponding to the 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 a? At the a 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 a-0.05 level, we fall 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 insufficient evidence at the 0.05 level to conclude that the drug has changed the mean pH level of the blood