A study is being performed to see if there is a correlation between the concentration of chromium in the blood and a suspected disease. Blood samples from a series of volunteers with a history of the disease and other indicators of susceptibility are analyzed and compared with the results from the analysis of samples from healthy control subjects. From the following results, determine whether the difference between the two groups can be ascribed to chance or whether they are real (i.e. Do the two groups have statistically different results at the 95% confidence limit?). [Hint: You must decide if the standard deviations of the two methods are statistically the same first.]

A study is being performed to see if there is a correlation between the concentration of chromium in the blood and a suspected disease. Blood samples from a series of volunteers with a history of the disease and other indicators of susceptibility are analyzed and compared with the results from the analysis of samples from healthy control subjects. From the following results, determine whether the difference between the two groups can be ascribed to chance or whether they are real (i.e. Do the two groups have statistically different results at the 95% confidence limit?). [Hint: You must decide if the standard deviations of the two methods are statistically the same first.]

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

A large clinical trial of the effect of diet on breast cancer assigned women at random to either a normal diet or a low-fat diet. To check that the random assignment did produce comparable groups, we can compare the two groups at the start of the study. Asked if there is a family history of breast cancer: 1276 of the 5964 women in the low-fat group and 1507 of the 7726 women in the control group said "Yes." If the random assignment worked well, there should not be a significant difference in the proportions with a family history of breast cancer. How significant is the observed difference? State: Is there evidence of a difference in the proportion of women with a family history of breast cancer between the treatment and control groups? Plan: Let pi be the proportion for the treatment group, and Pz the proportion for the control group. State the hypotheses for your test. Ha:Pi + P2 Solve: Give the value of the test statistic. Use the calculator. Select an answer ♥ Ho:pi = p2 What is the…
29 percent of all Samsung cell phones are submitted for service while under warranty. Of these, 66 percent can be repaired, whereas the other 34 percent must be replaced with new units. If a company purchases 12 Samsung cell phones, what is the probability that exactly 2 will end up being replaced under warranty? What would the mean number of cell phones being replaced under warranty be? What would be the variance be for the cell phones being replaced by warranty?.
Postpartum depression and anxiety (PPD), is a common medical condition affecting mothers and their families after the birth of a baby. The CDC estimated that 18% of women who have recently given birth suffer from PPD. However, this research only reflected self-reported cases. Therefore, one group dedicated to helping women and their families with PPD believes that the true percentage of women who suffer from PPD is much higher. The group conducts a simple random sample of 112 women who had given birth in the last year and discovers that 26 of them report having PPD. Based on this evidence, can the group claim that the true percentage of women who have PPD is greater than 18%? Use a 0.05 level of significance. Step 3 of 3 : Draw a conclusion and interpret the decision. 1. We reject the null hypothesis and conclude that there is sufficient evidence at a 0.05 level of significance that the true percentage of women who have PPD is greater than 18%. 2. We fail to reject the…
A manufacturer of laptop computers claims that only 1% of their computers are defective. In a sample of 600 computers, it was found that 3% were defective. If the proportion of defectives were really only 1%, there would be than 1 chance in 1000 of getting such a large proportion of defective laptops in the sample. Is there statistically significant evidence against the manufacturer's claim? Why or Why not?
Most hospitals now have signs posted everywhere banning cell phone use. These bans originate from studies on earlier versions of cell phones. In one such experiment, out of 510 tests with cell phones operating at near-maximum power, 160 disrupted a piece of medical equipment enough to hinder interpretation of data or cause equipment to malfunction. Test whether this estimate is different from random chance What is H0, HA, Test statistic?
Annie is concerned over a report that "a woman over age 40 has a better chance of being killed by a terrorist than of getting married." A study found that the likelihood of marriage for a never-previously-wed, 40-year-old university-educated American woman was 2.4%. To demonstrate that this percentage is too small, Annie uses her resources at the Baltimore Sun to conduct a simple random sample of 440 never-previously-wed, university-educated, American women who were single at the beginning of their 40s and who are now 45. Of these women, 12 report now being married. Does this evidence support Annie’s claim, at the 0.02 level of significance, that the chances of getting married for this group is greater than 2.4%? Step 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. Step 2 of 3: Compute the value of the test statistic. Round your answer to two decimal places Step 3 of 3: Draw a conclusion and interpret the decision.
Over the past few decades, public health officials have examined the link between weight concerns and teen girls' smoking. Researchers surveyed a group of 273 randomly selected teen girls living in Massachusetts (between 12 and 15 years old). After four years the girls were surveyed again. Sixty-three said they smoked to stay thin. Is there good evidence that more than thirty percent of the teen girls smoke to stay thin? Correctly identify the null and alternative hypotheses:
A large company that produces a "tat-burner pill claims an average Ioss of 20 pounds in the first month. A consumer advocacy group believes that this claim is actually just "hype" intended to sell more of the compound. The advocacy group Would like to obtain statistical evidence about this issue and takes a random sample of 100 consumers who responded that they had purchased the pill but didn't know what the survey was about. They find that these 100 people lost an average of 18 pounds. Let the standard deviation of the population be 7.5 pounds. Clearly state the hypotheses, obtain the test statistic and p-value, and state the decision and conclusion. Show all your work.
Does buttered toast fall face down? Data was collected to test this. 40 slices of toast (each with butter on one side) were dropped (from the same height). 24 slices (60%) landed buttered side down. We would like to use the results of this study to determine if there is statistical evidence that toast tends to land buttered side down more than 50% of the time.
Annie is concerned over a report that "a woman over age 40 has a better chance of being killed by a terrorist than of getting married." A study found that the likelihood of marriage for a never-previously-wed, 40-year-old university-educated American woman was 3.2%. To demonstrate that this percentage is too small, Annie uses her resources at the Baltimore Sun to conduct a simple random sample of 436 never-previously-wed, university-educated, American women who were single at the beginning of their 40s and who are now 45. Of these women, 20 report now being married. Does this evidence support Annie’s claim, at the 0.02 level of significance, that the chances of getting married for this group is greater than 3.2%? Step 1 of 3 : State the null and alternative hypotheses for the test. Circle the answer below. H0: p=0.032: Ha: p 0.032 A.<B.>C.≠ Step 2 of 3: Compute the value of the test statistic. Sep 3 of 3: Draw a conclusion and interpret the decision.