A sheriff cracks down on speeders. Following the crackdown, the sheriff takes a random sample (n...
A sheriff cracks down on speeders. Following the crackdown, the sheriff takes a random sample (n = 100) of vehicle speeds on the roadway. The sample data: sample mean, 47 mph; sample standard deviation, 8 mph. (i) Using the sample standard deviation as a substitute for the population standard deviation, what is the standard error of the sample mean? (ii) Using the ±2 shortcut, what is the 95 percent confidence interval of the sample mean?
2. A skeptical county commissioner claims that the crackdown had no effect and that average speed on the roadway is still 50 mph. (i) Is the skeptic on solid statistical ground? (ii) Explain how you know.”
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A sheriff cracks down on speeders. Following the crackdown, the
sheriff takes a random sample (n...
Using a random sample of n = 50, the sample mean is = 13.5. Suppose that...
Using a random sample of n = 50, the sample mean is = 13.5. Suppose that the population standard deviation is σ=2.5. Is the above statistical evidence sufficient to make the following claim μ ≠15: ?o: μ=15 ??: μ ≠15 α = 0.05. p value = 0 Interpret the results using the p value test. A) Reject Ho. B) Do not reject Ho.
I need this solved on Excel please 4. The following data were collected on speeds on...
I need this solved on Excel please
4. The following data were collected on speeds on H1, a major highway. Using Excel's statistical functions, complete the following questions. 90 75 57 64 68 60 82 67 SPEED (MPH) 78 57 71 52 65 63 69 61 a. What is the mean of the data set for speed on H1? b. What is the standard deviation of the data set for speed on H1? c. Construct a histogram for the speed...
1. Consider the following sample spot speed data. The speeds are in miles per hour Speed...
1. Consider the following sample spot speed data. The speeds are in miles per hour Speed Grou Lower Limit Upper Limit Mid-point Frequenc 27.5 32.5 37.5 42.5 47.5 52.5 57.5 62.5 67.5 72.5 77.5 82.5 87.5 92.5 25 30 35 40 45 50 22.6 27.6 32.6 37.6 42.6 47.6 52.6 57.6 62.6 67.6 72.6 77.6 82.6 87.6 2 14 25 60 65 70 75 80 85 90 4 (a) Calculate the sample mean speed (b) Calculate the sample median speed...
Which of the following is a true statement for any population with mean μ and standard deviation σ? I. The distribution of sample means for sample size n will have a mean of μ.
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1. In a simple random sample of n = 840 voters, X = 609 indicate that they will start holiday shopping this weekend. (a) Find the 95% confidence interval for p and the margin of error. (b) Use the six-step method of hypothesis testing to determine if the proportion is significantly different from 0.75. Use α = 0.05. (c) Is your conclusion the same with the test and the confidence interval? (d) How would the p-value change if you used...
3. Consider the following. n = 5 measurements: 3, 3, 1, 2, 5 Calculate the sample variance, s2, using the definition formula.
3. Consider the following. n = 5 measurements: 3, 3, 1, 2, 5 Calculate the sample variance, s2, using the definition formula. Calculate the sample variance, s2 using the computing formula. Calculate the sample standard deviation, s. (Round your answer to three decimal places.)4. A distribution of measurements is relatively mound-shaped with a mean of 60 and a standard deviation of 13. Use this information to find the proportion of measurements in the given interval. between 47 and 73 5. A distribution of...
A random sample of vehicles n=36 were selected and fitted with a new brake design. a standardized...
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A light bulb manufacturer claims that the mean life of a certain type of light bulb is 750 hours. If a random sample of 36 light bulbs has a mean life of 725 hours with a standard deviation of 60 hours. Use a=0.05
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5. I took a random sample of people from the 2000 U.S. Census and recorded the incomes. The sample size was n = 30 (with replacement). The average of the sample was $23606 and the standard deviation of the sample was $24757. Answer these questions using the statistics that I found from my sample. a) Find a 95% confidence interval for the mean income of the population. b) What assumptions must you make? c) Your confidence interval is of the...
I need this solved on Excel please
4. The following data were collected on speeds on H1, a major highway. Using Excel's statistical functions, complete the following questions. 90 75 57 64 68 60 82 67 SPEED (MPH) 78 57 71 52 65 63 69 61 a. What is the mean of the data set for speed on H1? b. What is the standard deviation of the data set for speed on H1? c. Construct a histogram for the speed...
1. Consider the following sample spot speed data. The speeds are in miles per hour Speed Grou Lower Limit Upper Limit Mid-point Frequenc 27.5 32.5 37.5 42.5 47.5 52.5 57.5 62.5 67.5 72.5 77.5 82.5 87.5 92.5 25 30 35 40 45 50 22.6 27.6 32.6 37.6 42.6 47.6 52.6 57.6 62.6 67.6 72.6 77.6 82.6 87.6 2 14 25 60 65 70 75 80 85 90 4 (a) Calculate the sample mean speed (b) Calculate the sample median speed...
3. Consider the following. n = 5 measurements: 3, 3, 1, 2, 5 Calculate the sample variance, s2, using the definition formula. Calculate the sample variance, s2 using the computing formula. Calculate the sample standard deviation, s. (Round your answer to three decimal places.)4. A distribution of measurements is relatively mound-shaped with a mean of 60 and a standard deviation of 13. Use this information to find the proportion of measurements in the given interval. between 47 and 73 5. A distribution of...
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