Suppose that a researcher is interested in estimating the mean systolic blood pressure, μ , of executives of major corporations. He plans to use the blood pressures of a random sample of executives of major corporations to estimate μ . Assuming that the standard deviation of the population of systolic blood pressures of executives of major corporations is 27 mm Hg, what is the minimum sample size needed for the researcher to be 99% confident that his estimate is within 4 mm Hg of μ ? Carry your intermediate computations to at least three decimal places. Write your answer as a whole number (and make sure that it is the minimum whole number that satisfies the requirements).

A laboratory claims that the mean sodium level, u, of a healthy adult is 143 mEq per liter of blood. To test this claim, a random sample of 50 adult patients is evaluated. The mean sodium level for the sample is 140 mEq per liter of blood. It is known that the population standard deviation of adult sodium levels is 10 mEq. Can we conclude, at the 0.1 level of significance, that the population mean adult sodium level differs from that claimed by the laboratory? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.)

An old medical textbook states that the mean sodium level for healthy adults is 140 mEq per liter of blood. A medical researcher believes that, because of modern dietary habits, the mean sodium level for healthy adults, u, now differs from that given in the textbook. A random sample of 23 healthy adults is evaluated. The mean sodium level for the sample is 147 mEq per liter of blood. It is known that the population standard deviation of adult sodium levels is 14 mEq. Assume that the population is normally distributed. Can we conclude, at the 0.10 level of significance, that the population mean adult sodium level differs from that given in the textbook? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H and the alternative hypothesis H₁. H₂:0 H₁ :0 (b) Determine the type of test statistic to…

A psychologist is studying the self image of smokers, which she measures by the self-image (SI) score from a personality inventory. She would like to estimate the mean SI score, µ, for the population of all smokers. She plans to take a random sample of SI scores for smokers and estimate u via this sample. Assuming that the standard deviation of SI scores for the population of all smokers is 85, what is the minimum sample size needed for the psychologist to be 95% confident that her estimate is within 12 of u? Carry your intermediate computations to at least three decimal places. Write your answer as a whole number (and make sure that it is the minimum whole number that satisfies the requirements). (If necessary, consult a list of formulas.)

Aldo, a highway safety inspector, is concerned about the potential for accidents caused by boulders that fall down a sandstone cliff beside a main highway. As part of an accident simulator, Aldo models the boulders' weights using a normal distribution with a mean of 556 kg and a standard deviation of 100 kg find the percentage of boulders that weigh less than  520kg or more than 592kg according to the model.   .

The nicotine content in cigarettes of a certain brand is normally distributed with mean (in milligrams) u and standard deviation o = 0.1. The brand advertises that the mean nicotine content of their cigarettes is 1.5 mg. Now, suppose a reporter wants to test whether the mean nicotine content is actually higher than advertised. He takes measurements from a SRS of 15 cigarettes of this brand. The sample yields an average of 1.6 mg of nicotine. Conduct a test using a significance level of a = 0.05. (a) The standardized test statistic (b) The critical value (endpoint of Rejection Region) is z* = (c) The final conclusion is OA. The nicotine content is probably higher than advertised. B. There is not sufficient evidence to show that the ad is misleading.

A sample of size 31 was gathered from high school seniors to estimate how many intended to attend the state university. It is known that the proportion of the population answering "yes" was 0.7. What are the mean and standard deviation, and standard error of the mean of this sample? mean = E(p) = %3D standard error = SD(p) (accurate to 3 decimal places)

During the busy season, it is important for the shipping manager at ShipMundo to be able to estimate the time it takes the loading crew to load a truck. The shipping manager has found that she can model the load times using a normal distribution with a mean of 152 minutes and a standard deviation of 15 minutes. Use this table or the ALEKS calculator to find the percentage of load times between 116 minutes and 149 minutes according to the model. For your intermediate computations, use four or more decimal places. Give your final answer to two decimal places (for example 98.23%).

It takes an average of 14 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 43 injured patients to immediately tell the truth about the injury and noticed that they averaged 12.5 minutes for their blood to begin clotting after their injury. Their standard deviation was 3.1 minutes. What can be concluded at the the αα = 0.01 level of significance? For this study, we should use     The null and alternative hypotheses would be:       H0:H0:                   H1:H1:               The test statistic     =  (please show your answer to 3 decimal places.) The p-value =  (Please show your answer to 4 decimal places.) The p-value is     αα Based on this, we should      the null hypothesis. Thus, the final conclusion is that ... The data suggest the population mean is not significantly different from 14 at αα = 0.01, so there is statistically significant…