1. A study of 40 English professors showed that they spend, on average, 12.6 minutes correcting a student's term paper. The standard deviation was 2.5 minutes. Construct the 99% confidence interval of the mean for all term papers.

Q: In a survey of 600 personnel directors, 40% thought that they would be hiring new personnel over the…

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Q: You read in a U.S. Census Bureau report that a 90% confidence interval for the median income in 2012…

A: It is given that 90% confidence interval for the median income in 2012 of American households was…

Q: If you need to make a 98% confidence interval for a proportion, and the margin of error is to be no…

A: Given information:  Confidence level = 98% Margin of error (e) = 0.025 Let proportion (p) = 0.5 The…

Q: Question 1

A: The formula for the sample size is as follows:

Q: 1. The mean and standard deviation for the quality grade point averages of a random sample of 36…

A: "Since you have asked multiple questions, we will solve the first question for you. If you want any…

Q: For a single sample of n = 16 scores, the tabled t values used to determine the 99 percent…

A: Given: n = 16 Confidence Interval = 99% α=1-0.99=0.01α2=0.012=0.005 Degrees of freedom:…

Q: 2. Discuss the effect of following on the width of a confidence interval. a. Confidence level c.…

A: effect of different components on width of confidence interval is as follows : a) Confidence level :…

Q: In a situation where the sample size was decreased from 39 to 29 in a normally distributed data set,…

A: Confidence interval formula is given by

Q: 1- The Internal Revenue Service is studying contributions to charity. The mean calculated from a…

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Q: a recent study of 100 people in Burlingame found that 19 were obese.  Find the 90% confidence…

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Q: If a confidence interval for the mean is (34≤μ≤86)(34≤μ≤86), a) What is the point estimate?    b)…

A: (a) The point estimate is 60, which is obtained below: Point estimate=Upper limit+lower…

Q: Given the data from ten (10) randomly selected European females about their foot length. 22.5  24.7…

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Q: Which of the following would result in the narrowest confidence interval? A. 80% confidence level…

A: The narrowest confidence interval will result from larger sample size and a smaller confidence…

Q: 16- An economist is interested in studying the incomes of consumers in a particular country. The…

A: We have to find ci.

Q: The International Nanny Association reports that in a sample of 528 in-home child care providers…

A: Solution:Part (a): Finding the 95% confidence interval for the true proportion of all nannies who…

Q: How many subjects would be needed to ensure that 95% confidence interval estimate of BMI had a…

A: Generate 95% confidence interval for the given data .    Mean & standard deviation :  The sample…

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: 3. A random sample of 16 drinks from a soft drink machine has the following contents(ml): 250 280…

A: Given: Sample size n = 16 Population is Normally distributed. Population mean = mu= 275 Level of…

Q: For a group of 45 students taking a PSDTF test, the mean heart rate was 96 beats per minute, and the…

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Q: A researcher calculates a 90% confidence interval of (0.24,0.4) for a proportion. What was the…

A: Given :confidence level = 90% confidence interval = (0.24,0.4) p is unknown, so p=0.5 We want to…

Q: b. Construct a confidence interval suitable for testing the claim that the mean IQ scores for…

A: b. Here, medium lead level is the first sample and high-level lead is the second sample.   The…

Q: A bank wishes to estimate the mean credit card balance owed by its customers. The population…

A: Determine the number of customers needs to be sampled. The number of customers needs to be sampled…

Q: 2. In order to investigate the relationship between mean job tenure in years among workers who have…

A: Given:n1=155, x1=5.2, s1=1.3n2=210, x2=5, s2=1.5   Then, the pooled standard deviation…

Q: 7. If n=25 and the sample standard deviation is 15, construct a 95% confidence interval for the true…

A: We have given that, n = 25 , Standard deviation = 15, We need to construct the 95% confidence…

Q: Suppose that a safety group surveyed 800 drivers. Among those​ surveyed, 83​% said that careless or…

A: Given Information :  Suppose that a safety group surveyed 800 drivers. Among those​ surveyed, 83​%…

Q: 3.1 Construct a 95% confidence interval for the proportion of South Africans who avoided fat in…

A: From given data we have : for 2010 survey sample size=n1=1250 Proportion (Avoided fat)=p^1=0.55 for…

Q: A sociologist develops a test to measure attitudes about public transportation, and 20 randomly…

A: The confidence interval is a set of elements that have been imagined to comprise, with a specified…

Q: An investigative reporter contacts a random sample of hotels, and finds a 95% confidence interval…

A: Given that  The 95% confidence interval for the proportion of hotels in the united states have…

Q: If n=150 and ˆpp^ (p-hat) =0.25, find the margin of error at a 90% confidence level

A: n = 150p^ = 0.2590% confidence level

Q: 7. For the upcoming football season, the athletic department is considering increasing the price for…

A: We have given that, Sample mean (x̄) = 150$ and standard deviation deviation (s) = 40$ and sample…

Q: (b) Use a 99% confidence interval to estimate the mean percent change in the population. FILE O…

A: (b) The mean percent is, x¯=∑xn=-4.7-2.5-4.9-2.7+⋯-5.147=-168.647=-3.5872 The mean percent is…

Q: Market research indicates that a new product has the potential to make the company an additional…

A: It is given that,Sample mean = $3.8 million.Sample standard deviation, s is $1.8 million.The sample…

Q: 12. Which of the following values falls outside of the confidence interval? Mean number of students…

A: From the provided information, The confidence interval is 28.4±3.7

Q: 1(c). Construct a 99% confidence interval for the true proportion of people who liked the chocolate…

A: here use given data table

Q: 2.13 The t-value that would be used to construct a 99% confidence interval for the mean with a…

A: We have given that  Sample size = n= 17   , 99% confidence  So, level of significance = alpha = 0.01…

Q: b) A random sample of records of 10 night shifts at the emergency section at the Nairobi hospital…

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Q: If X̅ = 65, ? = 20 ??? ? = 36, construct a 95% confidence interval estimate for the population mean,…

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Q: If the sample mean is 70 and the standard error of the sample mean is 8, what will be the 90%…

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Q: If a confidence interval for the mean is (41≤μ≤84)(41≤μ≤84), a) What is the point estimate?    b)…

A: a) What is the point estimate?

Q: If a confidence interval for the mean is (43≤μ≤82)(43≤μ≤82), a) What is the point estimate?    b)…

A: Given the confidence interval for the population mean in tri-linear inequality form: Hence,

Q: 12.What is the sample size needed if the margin of error is 30 and the standard deviation of 45 with…

A: (12)  We have given that,  Confidence level (C.I) = 98% , standard deviation (σ) = 45 and margin of…

Q: If you obtained one thousand 95% confidence intervals for a population mean, μ, roughly how many of…

A: A 95% confidence interval means that if we take 100 different samples and determine a 95% confidence…

Q: he following stemplot shows the swimming speeds, in kilometers per hour  (km/h), for a random sample…

A: xbar = 9.771 s = 0.944 n = 31

Q: 2) The following data represent the number of passengers per flight in a random sample of 20 flights…

A: Confidence Interval: In statistics, we can say a range of values of the specified population…

Q: For a group of 10 men subjected to a stress situation, the mean number of heart beats per minute was…

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Q: For a sample with a mean of 10, a std of 5 and an n of 30, what is the lower bound of the 95%…

A: Given data, x=10σ=5n=30z-value at 95% confidence is Zc=1.96

Q: 1) Jaimie does a study on how many students have passed his classes in the past. He finds that 2739…

A: The random variable students who pass follow normal distribution. The number of successes is 2739.…

Q: In the construction of an 88% Confidence Interval for a population mean u, a has the value of

A: Incomplete

Q: If n=420 and ˆpp^ (p-hat) =0.19, find the margin of error at a 95% confidence level

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Q: on the data she gathers. Which one of the following combinations of sample size and confidence level…

A: here AS PER GUIDELINES I HAVE CALCULATED FIRST MAIN QUESTION , AS YOU HAVE POSTED MULTIPLE DIFFRENT…