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11. [0.34/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.020.MI. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A study of parental empathy for sensitivity cues and baby temperament (higher scores mean more empathy) was performed. Let x, be a random variable that represents the score of a mother on an empathy test (as regards her baby). Let x2 be the empathy score of a father. A random sample of 36 mothers gave a sample mean of x, = 69.04. Another random sample of 34 fathers gave x2 = 57.68. Assume that , = 11.55 and 02 = 11.45. (a) Let u, be the population mean of x, and let My be the population mean of x2. Find a 99% confidence interval for /1 - #2. (Round your answers to two decimal places.) lower limit upper limit [b) Examine the confidence interval and explain what it means in the context of this problem. Does the confidence interval contain all positive, all negative, or both positive and negative numbers? What does this tell you about the relationship between average empathy scores for mothers compared with those for fathers at the 99% confidence level? Because the interval contains only positive ve a higher mean empathy score. O Because the interval contains both po numbers, we can not say that the mothers have a higher mean empathy score. We can not make any conclusions using this confidence interval. O Because the interval contains only negative numbers, we can say that the fathers have a higher mean empathy score. Need Help? Read It Master ItSubmitted 12. [0.34/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.024.5. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER At Community Hospital, the burn center is experimenting with a new plasma compress treatment. A random sample of nj = 310 patients with minor burns received the plasma compress treatment. Of these patients, it was found that 262 had no visible scars after treatment. Another random sample of n2 = 422 patients with minor burns received no plasma compress treatment. For this group, it was found that 101 had no visible scars after treatment. Let p, be the population proportion of all patients with minor burns receiving the plasma compress treatment who have no visible scars. Let p2 be the population proportion of all patients with minor burns not receiving the plasma compress treatment who have no visible scars. LOL USE SALT (a) Find a 90% confidence interval for P1 - P2. (Round your answers to three decimal places.) lower limit upper limit (b) Explain the meaning of the confidence interval found in part (a) in the context of the problem. Does the interval contain numbers that are all positive? all negative? both positive and negative? At the 90% level of confidence, does treatment with plasma compresses seem to make a difference in the proportion of patients with visible scars from minor burns? O We can not make any conclusions using this confidence interval. Because the interval contains only positive numbers, we can say that there is a higher proportion of patients with no visible scars among those who received the treatment. O Because the interval contains both pos . we can not say that there is a higher proportion of patients with no visible scars among those who received the treatment. Because the interval contains only negative numbers, we can say that there is a higher proportion of patients with no visible scars among those who did not receive the treatment. Need Help? Read it Watch itSubmitted 13. [0.2/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 7.4.026.MI.S. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER In the Focus Problem at the beginning of this chapter, a study was described comparing the hatch ratios of wood duck nesting boxes. Group I nesting boxes were well separated from each other and well hidden by available brush. There were a total of 465 eggs in group I boxes, of which a field count showed about 268 hatched. Group II nesting boxes were placed in highly visible locations and grouped closely together. There were a total of 783 eggs in group II boxes, of which a field count showed about 280 hatched. LO USE SALT (a) Find a point estimate , for pyr the proportion of eggs that hatch in group I nest box placements. (Round your answer to four decimal places.) P1= Find a 95% confidence interval for p1. (Round your answers to three decimal places.) lower limit upper limit (b) Find a point estimate py for pyr the proportion of eggs that hatch in group II nest box placements. (Round your answer to four decimal places.) P2 = Find a 95% confidence interval for p2. (Round your answers to three decimal places.) lower limit upper limit (c) Find a 95% confidence interval for P1 - P2. (Round your answers to three decimal places.) lower limit upper limit2. [-/1 Points] DETAILS BBUNDERSTAT12 7.R.002. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER x = $ Suppose you are told that a 95% confidence interval for the average price of a gallon of regular gasoline in your state is from $2.93 to $4.21. Use the fact that the confidence interval for the mean is in the form x - E to x + E to compute the sample mean and the maximal margin of error E. (Round your answers to two decimal places.) E = $ Need Help? Read It Watch it4. [-/1 Points] DETAILS BBUNDERSTAT12 7.R.004. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Anystate Auto Insurance Company took a random sample of 376 insurance claims paid out during a 1-year period. The average claim paid was $1555. Assume o = $256. Find a 0.90 confidence interval for the mean claim payment. (Round your answers to two decimal places.) lower limit $L upper limit Find a 0.99 confidence interval for the mean claim payment. (Round your answers to two decimal places.) lower limit $ upper limit Need Help? Read It5. [-/1 Points] DETAILS BBUNDERSTAT12 7.R.005. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Three experiments investigating the relation between need for cognitive closure and persuasion were performed. Part of the study involved administering a "need for closure scale" to a group of students enrolled in an introductory psychology course. The "need for closure scale" has scores ranging from 101 to 201. For the 66 students in the highest quartile of the distribution, the mean score was x = 177.30. Assume a population standard deviation of