12. (Two Samples) According to a survey, the mean price of gasoline in the United Stateswas $1.20 per gallon in 1995 and $1.10 per gallon in 1994. (U.S. News & WorldReport, June 12, 1995). Suppose these means were based on random samples of 100gasoline stations for 1995 and 120 gasoline stations for 1994. Also, assume that thesample standard deviations were $0.11 for 1995 and $0.10 for 1994.a. Construct a 98% confidence interval for the difference between the mean gasolineprices for 1995 & 1994.b. Test at the 1% significance level if the mean gasoline price was higher in 1995than in 1994.

Step 1:Determine the given variables x1ˉ=1.2,x2ˉ=1.1,n1=100,n2=120,s1=0.11,s2=0.1Step…

Answered: 12. (Two Samples) According to a…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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3. An extensive study of the cost of health care in the United States presented data showing that the mean spending per Medicare enrollee in 2003 was $6883 (Monday, Fall 2003). To investigate differences across the country, a researcher took a sample of 49 Medicare enrollees in Indianapoli with a mean spending of $5978.32 and a standard deviation is $2513.
4. A research article reported that for a random sample of 850 meal purchases made at fast food chain A, the mean sodium content was 1,687 mg, and the standard deviation was 823 mg. For a random sample of 2,107 meal purchases made at fast food chain B, the mean sodium content was 1,474 mg, and the standard deviation was 811 mg. Based on these data, is it reasonable to conclude that there is a difference in mean sodium content for meal purchases at fast food chain A and meal purchases at fast food chain B? Use ? = 0.05. (Use ?1 for fast food chain A and ?2 for fast food chain B.) State the appropriate null and alternative hypotheses. A) H0: ?1 − ?2 = 0 Ha: ?1 − ?2 < 0 B) H0: ?1 − ?2 = 0 Ha: ?1 − ?2 ≠ 0 C) H0: ?1 − ?2 ≠ 0 Ha: ?1 − ?2 = 0 D) H0: ?1 − ?2 > 0 Ha: ?1 − ?2 = 0 E) H0: ?1 − ?2 = 0 Ha: ?1 − ?2 > 0 t=_________ P-value_______ State the conclusion in the problem context. A) We reject H0. It is not reasonable to conclude that there is a…
If the weekly grocery expenditure of households in a certain urban market is known to be normally distributed with a mean of $150 and a standard deviation of $30, what proportion of the households spend between $110 and $160 per week on groceries?
During a quality assurance check, the actual contents (in grams) of six containers of protein powder were recorded as 1526, 1528, 1503, 1513, 1531, and 1516. (a) Find the mean and the median of the contents. (b) The third value was incorrectly measured and is actually 1519. Find the mean and the median of the contents again. (c) Which measure of central tendency, the mean or the median, was affected more by the data entry error? (a) The mean is 1519.5. (Round to one decimal place as needed.) The median is 1521 (Type an integer or a decimal. Do not round.) (b) The mean is (Round to one decimal place as needed.)
Imagine that every elementary school in California is measured on several characteristics and then given an overall Quality Score. In Los Angeles Unified School District, the schools have an average (mean) quality score of 101.8 with a standard deviation of 7.2. One school in Los Angeles, Carver Elementary, gets a quality score of 104.5. In San Francisco Unified School District, the schools have an average (mean) quality score of 102.3 with a standard deviation of 9.4. One school in San Francisco, Bryant Elementary, gets a quality score of 99.5. Find the Z-scores for both of these two schools (Carver Elementary in Los Angeles, and Bryant Elementary in San Francisco)
3. A certain breed of cat has weights which are normally distributed with a mean of 6.2 pounds, and a standard deviation of .8 pounds. What would be the z-score of a cat which weighed 7.4 pounds? 1.50 1.20 -1.50 -1.20
A study reported on essential organic molecules and a Normal model can be used to describe these levels in adults. If the mean is 194 mg/dL and a standard deviation is 28, complete the following questions. a) Draw and label the Normal model. b) What percent of adults do you expect to have this essential organic molecule, cholesterol, levels over 210 mg/dL? c) What percent of adults do you expect to have cholesterol levels between 150 and 170 mg/dL? d) Estimate the interquartile range of cholesterol levels. IQR=___________mg/dL e) Above what value are the highest 15% of adults' cholesterol levels? ___________mg/dL
According to the U.S. Census, the average adult woman is the United States is 65 inches tall and the standard deviation is 3 inches. If Zsike is 67 inches tall, what is her z-score?
One year Terry had the lowest ERA (earned-run average, mean number of runs yielded per nine innings pitched) of any male pitcher at his school, with an ERA of 3.02. Also, Karen had the lowest ERA of any female pitcher at the school with an ERA of 3.24. For the males, the mean ERA was 4.364 and the standard deviation was 0.639. For the females, the mean ERA was 3.801 and the standard deviation was 0.959 Find their respective z-scores. Which player had the better year relative to their peers, Terry or Karen? (Note: In general, the lower the ERA, the better the pitcher.) Terry had an ERA with a z-score of Karen had an ERA with a z-score of (Round to two decimal places as needed) Which player had a better year in comparison with their peers? OA. Terry had a better year because of a higher z-score. OB. Karen had a better year because of a lower z-score. OC. Terry had a better year because of a lower z-score. O D. Karen had a better year because of a higher z-score. GIL
2. The blood cholesterol levels of men age 55 to 64 are approximately Normal, with mean 222milligrams per deciliter (mg/dl) and standard deviation 37 mg/dl. A random sample of 58individuals will be collected and the sample mean cholesterol level will be computed. a. What is the mean of the sample mean? b. What is the standard deviation of the sample mean?
Is a measure of 29 inches "far away" from a mean of 19 inches? Suppose the data come from a sample whose standard deviation is 2 inches. A. How many standard deviation is 29 inches from 19 inches? b. Is 29 inches far away from a mean of 19 inches? c. Suppose the standard deviation of the underlying data is 7 inches. Is 29 inches far away from a mean of 19 inches?
A sample of 281 Al products sold at The Yes Buy located at Finch and Keele has a mean of $74.83 and a median of $68.88. Later, it was discovered that an observation which was recorded incorrectly as "$90.25" but the actual value should be "$95.75". If we make this correction to the data, then what is the sample mean, median, mode and standard deviation?

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