= 30 df Fail to reject H0 a value this extreme may occur by chance alone about 23% of the time. We lack strong evidence that there are fewer than 36 raisins per box. 5. An experiment on the side effects of pain relievers assigned arthritis patients to one of several pain medications. Of the 440 patients who took one brand of pain reliever, 23 suffered some symptom.” Does the experiment provide strong evidence that fewer than 10% of patients who “adverse take this medication have adverse symptoms? The data came from an experiment, and presumably they randomly assigned to treatment. The population of patients taking the medicine is likely to be greater than 4400. Reject H0,, a test statistic this small may occur by chance alone well less than 1% of the time. We have strong evidence that the true proportion of adverse symptoms is less than 10%. A department store stocks blue jeans that are identical except for color. A random sample of 32 6. sales showed the following purchases: Number sold Color Number sold Faded blue denim 13 Darker blue denim 8 Traditional blue 6 5 Does this data indicate that one color of jeans is preferred over the others, or are consumers buying the jeans in equal proportions? A: We are given a random sample. All expected cell counts are greater than 5. Expected counts are 8,8,8,8. Fail to reject H0 at a value this extreme may occur by chance alone about 19% of the time. We lack evidence that consumers have different preferences for various jean colors. 7. Poisoning by the pesticide DDT causes tremors and convulsions. In a of DDT poisoning, researchers fed several rats a measured amount of DDT. They then made measurements on the rats’ nervous systems that might explain how DDT poisoning causes tremors. One important variable was the refractory period,” the time required for a nerve to recover after a stimulus. This period “absolute varies normally. Measurements on ten rats gave the data below (in milliseconds). 1.5 2.0 1.7 1.9 1.8 1.6 2.15 1.75 1.50 3.01
df = 30 Fail to reject H0 a value this extreme may occur by chance alone about 23% of the time. We lack strong evidence that there are fewer than 36 raisins per box. 5. An experiment on the side effects of pain relievers assigned arthritis patients to one of several pain medications. Of the 440 patients who took one brand of pain reliever, 23 suffered some “adverse symptom.” Does the experiment provide strong evidence that fewer than 10% of patients who take this medication have adverse symptoms? The data came from an experiment, and presumably they randomly assigned to treatment. The population of patients taking the medicine is likely to be greater than 4400. Reject H0,, a test statistic this small may occur by chance alone well less than 1% of the time. We have strong evidence that the true proportion of adverse symptoms is less than 10%. 6. A department store stocks blue jeans that are identical except for color. A random sample of 32 sales showed the following purchases: Number sold Color Number sold Faded blue denim 13 Darker blue denim 8 Traditional blue 6 5 Does this data indicate that one color of jeans is preferred over the others, or are consumers buying the jeans in equal proportions? A: We are given a random sample. All expected cell counts are greater than 5. Expected counts are 8,8,8,8. Fail to reject H0 at a value this extreme may occur by chance alone about 19% of the time. We lack evidence that consumers have different preferences for various jean colors. 7. Poisoning by the pesticide DDT causes tremors and convulsions. In a of DDT poisoning, researchers fed several rats a measured amount of DDT. They then made measurements on the rats’ nervous systems that might explain how DDT poisoning causes tremors. One important variable was the “absolute refractory period,” the time required for a nerve to recover after a stimulus. This period varies normally. Measurements on ten rats gave the data below (in milliseconds). 1.5 2.0 1.7 1.9 1.8 1.6 2.15 1.75 1.50 3.01
Stats%20Handout%2013.5ans.docx