uppose an economist wishes to estimate the mean commute time of workers in Westchester County. The economist obtains a random sample of 31 commutes in Westchester County and finds the sample mean to be 31.2 minutes and the sample standard deviation to be 12.1 minutes. Construct and interpret a 90% confidence interval for the mean commute time in Westchester County.               Construct and interpret a 95% confidence interval for the mean commute time in Westchester County.

Q: 3- Car and Driver Magazine tested a random sample of 9 hybrid cars and found their MPG to be 42, 51,…

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Q: In a random sample on 200 airline passengers, 84 said they would like a window seat. What is the…

A: 1. The point estimate for the proportion of passengers wishing a window seat is, p^=xn=84200=0.42…

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Q: Determine the value of z, that would be used in constructing a 90%confidence interval for a 2.…

A: Z = x-μσ, Where μ = population mean,           σ = population variance,           x = observed…

Q: In a study of government financial aid for college students, it becomes necessary to estimate the…

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Q: Calculate a ninety-nine (99) percent confidence interval for µ, where n = 100, sample mean = 38, and…

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Q: In a transportation study of 27 large cities it was found that the number of motor vehicles per…

A: Given : Sample size (n) = 27 Sample mean (X¯) = one.34 i.e 1.34 Sample SD (S) = 0.46 Confidence…

Q: The Greater Pittsburgh Area Chamber of Commerce wants to estimate the mean time workers who are…

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Q: The General Social Survey asked, “How many emails do you send in a day?” The results of 928…

A: Given information Sample size, n = 928 Mean, x-bar = 10.4 Standard deviation, σ = 28.5 Since sample…

Q: In a survey, 24 people were asked how much they spent on their child's last birthday gift results…

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Q: Explain which would result in a wider large-sample confidence interval for : a 90%pconfidence level…

A: The z critical value for 95% confidence interval is 1.96 and the z-critical value for 90% confidence…

Q: Suppose you plan to take a survey of Math&146 students asked how many miles they commute from their…

A: Given,Confidence Interval = 95%ME= Margin of Error =1.5σ=Population Standard Deviation=5.3

Q: The National Association of Colleges (NAC) reported in 2003 that the mean starting salary for…

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Q: In a survey, 28 people were asked how much they spent on their child's last birthday gift. The…

A: Since population standard deviation is unknown, Use t-distribution to find t-critical value. Find…

Q: Define a confidence interval or margin of error and discuss the impact of sample size at it…

A: Let's define true population mean CI for a sample of size n (n<30) x¯±tsnwhere s=sample standard…

Q: 6. A food snack manufacturer samples 7 bags of pretzels off the assembly line and weighs their…

A: The confidence interval measure the range where the true population parameter exist. If the…

Q: Calculate the mean and 90% confidence interval for the data set.

A: The mean of the data is calculated as follows: x=1n∑xi=24.3986=4.066 The sample standard deviation…

Q: Determine the margin of error for the confidence interval for the mean: 21+1.2 The margin of error…

A: Confidence Interval formula for mean is given by, => (X bar + - z* sigma/√n) Where X bar is mean.…

Q: In analyzing the city and highway fuel efficiencies of many cars and​ trucks, the mean difference in…

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Q: B. Construct a 95% confidence interval estimate of 4-4, the difference between the mean weight of…

A: Given Information: B) 95% confidence interval estimate of difference between the mean weight of…

Q: The manager of a fast-food restaurant wishes to estimate the mean waiting time customers spend at…

A: It is given that the sample size is n=56. The sample mean waiting time is x¯=6.35. The sample…

Q: In a survey, 14 people were asked how much they spent on their child's last birthday gift. The…

A: From the given information, Sample size n =14 Sample mean, x̅=$49.5 Sample standard deviation,…

Q: Mr. Thomas of Wilmer Amina Carter High School (a large urban high school) wants to know what…

A: given that,possible chances (x)=85size(n)=152success rate ( p )= x/n = 0.5592

Q: Fifteen SmartCars were randomly selected and the highway mileage of each was noted. The analysis…

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Q: Recent business graduates currently employed in full-time positions were surveyed. Family…

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Q: The Greater Pittsburgh Area Chamber of Commerce wants to estimate the mean time workers who are…

A: Given: n=15 Using the excel formula "=AVERAGE(A2:A16)" the sample mean x¯=35.0667 Using the excel…

Q: Construct a 95% confidence interval for the true average number of visitors per day to a local game…

A: We have given that the 95% confidence interval with mean 32.5, standard deviation 4.5 and sample…

Q: Fifteen Smart Cars were randomly selected and the highway mileage of each was noted. The analysis…

A: Solution: Let X be the highway mileage of smart car. From the given information, x-bar=47 miles per…

Q: The amounts (in ounces) of juice in eight randomly selected juice bottles are: 15.4  15  15.7  16…

A: Given data, 15.4,  15,  15.7,  16 , 15.4,  15.1 , 15.7,  15.3   From given data, sample mean is…

Q: In a survey, 12 people were asked how much they spent on their child's last birthday gift. The…

A: Since population standard deviation is unknown, Use t-distribution to find t-critical value. Find…

Q: A doctor claims that the mean number of hours of sleep that seniors in high school get per night…

A: From the provided information, The claim is that the mean number of hours of sleep that seniors in…

Q: The annual earnings​ (in dollars) of 35 randomly selected microbiologists are shown in the data…

A: Given information: The annual earnings (in dollars) of n = 35 randomly selected microbiologists are…

Q: We plan to sample parents in order to construct a 99% confidence interval for the proportion who…

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Q: college admissions officer takes a simple random sample of 80 entering freshmen and computes their…

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Q: Construct a 90% confidence interval for the population variance.

A: 31

Q: The General Social Survey is a survey of opinions and lifestyles of U.S. adults, conducted by the…

A: Given: n=81x¯=8.2s=9.84 The degrees of freedom is obtained as below: df=n-1=81-1=80 The value of t*…

Q: To decide what personnel requirements should be enforced, a hospital manager wants to estimate the…

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Q: In a survey, 23 people were asked how much they spent on their child's last birthday gift. The…

A: Givensample size(n)=23sample mean (x) = 31standard deviation (s) = 8α = 1-0.95=0.05α2=0.025degrees…

Q: Suppose that a safety group surveyed 1,200 drivers. Among those​ surveyed,78​% said that careless or…

A: Obtain the 99% confidence interval estimate for the true proportion in the population of all drivers…

Q: In a survey, 21 people were asked how much they spent on their child's last birthday gift. The…

A: Margin of error is the error due to random sampling. The margin of error decreases with increase in…

Q: (a) Calculate and interpret a 95% confidence interval for population mean cadence. (Ro

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Q: In a survey, 41 people were asked how much they spent on their child's last birthday gift. The…

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Q: Construct a 95% confidence interval for the average cable bill of all American household

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Q: 2. A sample of seven college wrestlers had an average weight of 267 pounds with a sample standard…

A: Given that  Sample size (n)=7  Sample mean = 267  Sample standard deviation (s)= 10  We have to find…

Q: The average weight of 35 randomly compact automobiles was 2680. The sample standard deviation was…

A: From the provided information, Sample size (n) = 35 Sample mean (x̅) = 2680 Sample standard…

Q: The instructorTanner is concerned about the amount of time teachers spend each week doing schoolwork…

A: 1.   The 95% confidence interval for  the mean number of hours per week a teacher spends working at…

Q: A 95% confidence interval for the mean weight of bags of potato chips packed by a machine was found…

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Q: The Aloha Taxi Cab Company of Honolulu, Hawaii, wants to estimate the mean life of tires on its…

A: Given that, Sample mean = 18280 Sample standard deviation = 1310 Sample size = 15 90% confidence…

Q: Determine the margin of error for the confidence interval for the mean: 16+1.5 The margin of error…

A: We have given confidence interval is- 16 ± 1.5 Since we know that, Confidence interval = the…

Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.