Is the margin of error for a confidence interval for a population equivalent to the standard deviation times the z-score value, or t-score value depending on the size of the population, for the probability of interest times the standard deviation of the population? Why or why not?

Q: A poll conducted in 2013 found that 52% of U.S. adult Twitter users get at least some news on…

A: Solution: From the given information,

Q: A researcher wants to determine the average daily wage of waiters in a certain fast-food company. He…

A: Given,margin of error(E)=85standard deviation(σ)=350.95α=1-0.95=0.05α2=0.025Z0.025=1.96     (from…

Q: Suppose the desired confidence level is fixed, then what is the effect of a larger sample size on…

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Q: What is meant by saying that a 1-a confidence interval is a. exact?b. approximately correct?

A: a.Confidence Interval:Confidence interval is the interval estimate of the population parameter. It…

Q: An organization advocating for health care reform has estimated the average cost for health care of…

A: Given : sample mean, x̄ = 13000  Margin of error , E = 1000

Q: What is the one exception to using the z score for confidence intervals?

A:

Q: Use the formula for a Confidence Interval for Two Proportions to calculate a 95% confidence interval…

A: Confidence interval: The (1-α)100 % confidence interval for proportion p1 – p2 is given by,

Q: 1. How is the expected length of a confidence interval related to the margin of error?

A: here use basic of confidence interval

Q: Generally speaking, what is the difference between a confidence interval and a prediction

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Q: The Pew Forum on Religion and Public Life reported on Dec. 9, 2009, that in a survey of 2003…

A:

Q: In an effort to estimate the mean amount spent per customer for dinner at a major Atlanta…

A: From the provided information, Sample size (n) = 49 Sample mean (x̅) = $24.80 Population standard…

Q: What are the Two Assumptions of Confidence Interval for μ Based on z?

A: Confidence interval: Confidence interval is the interval estimate of the population parameter. It is…

Q: Explain the Other Types of Confidence Intervals.

A:

Q: What is the impact on the confidence interval estimate if a larger sample is used?

A: Confidence interval:

Q: Suppose that you will be taking a random sample from a population and that you intend to find a 95%…

A: Solution: The confidence interval for the population mean is calculated by using the following…

Q: The Pew Forum on Religion and Public Life reported on Dec. 9, 2009, that in a survey of 2003…

A: Given : Sample size(n)=2003sample proportion(p^)=0.25confidence level (c)=0.99α=1-c   =1-0.99…

Q: Determine from a confidence interval whether a test is significant?

A: Null hypothesis states that there is no difference between populations or a set of given…

Q: a confidence interval inappropiately using a z statistics instead of a t statistic will give a…

A: When we use z instead of t in, it will result in a smaller margin of error and consequently narrower…

Q: Based on this output, what are the sample mean income and standard error of the mean income –…

A: By the given output, we can observe that Mean=$79189.87 Standard error of sample mean=$1663.489…

Q: Increasing the sample size will decrease the margin of error in your confidence interval.

A: Use the theory of confidence interval to solve this problem.

Q: process control engineer wishes to estimate the true proportion of defective computer chips by using…

A: GivenThe true proportion p=0.01Let the sample size be n.The Z critical value for 90% confidence…

Q: Unlike confidence intervals, hypothesis tests require that some predetermined population value be…

A: The confidence intervals, provide the range where the population mean or parameter will remain in…

Q: If the sample size is increased and the standard deviation and confidence level stay the same, then…

A: Margin of error:The margin of error helps in constructing confidence intervals, which gives a range…

Q: What is the sample size required to construct a 90% confidence interval for the population mean with…

A: Given,E=0.2z-value at 90% confidence is Zc=1.645Let the last two digits of your student ID is…

Q: If the standard deviation is increased and the sample size and the confidence level stay the same,…

A: Error=Z×σn where σ: standard deviation             Z: z-score for the given confidence level…

Q: What proportion of college students earn their undergraduate degrees in four years? A college…

A: The formula of the margin of error when the limits given are,

Q: "if the confidence level or P-value does not change very much when the conditions for use of the…

A: In general, t-test is used for small samples and samples are normally distributed. It is used when…

Q: As the sample standard deviation increases when all other parts of the confidence interval stay the…

A: We want tell the sample standard deviation increases when all other parts of the confidence interval…

Q: Explain the steps in computing a confidence interval for ρ?

A: Introduction: The steps to construct a confidence interval in general are: Identify a sample…

Q: Suppose our estimate for the mean score for the Player A group was 48 ± 5% SE (standard error). What…

A: Given: Point estimate = 48 Standard error = 5 Confidence level = 95%

Q: What is the 90% confidence interval of the mean?

A: A confidence interval is an interval that has the property that is very likely that the population…

Q: Suppose a drug for stomach discomfort is tested on 75 subjects, and the mean time for it to take…

A: Given: Sample size n = 75 Sample mean X = 200 Population standard deviation σ = 30 Formula Used:…

Q: if you increase the sample size and confidence level at the same time. what will happen to the width…

A: The formula for the confidence interval (say) for population mean is :  C.I= x ± zα/2.s2n As the…

Q: A narrower confidence interval for a population parameter with a given confidence level can be…

A: Here we need to determine whether the given statement is true or false. First we need to find if…

Q: What is the difference between the different confidence interval formulas?

A: Confidence interval is the estimate of the interval of an unknown population parameter. It provides…

Q: Derive the necessary expression for one-sided lower confidence interval for the population variance…

A: we know that if any random variable x follows normal distribution (population) with mean μ and…

Q: How can a confidence interval be used to test a hypothesis?

A: How can a confidence interval be used to test a hypothesis?

Q: Why do we use a t-distribution to compute confidence intervals for population means?

A:

Q: Although a confidence interval doesn't tell us the exact value of the true population parameter, we…

A: Confidence interval is the probability that a population parameter will fall between a set of values…

Q: When computing a confidence interval, the size of the error term depends on what?

A: The formula to calculate the error term for confidence interval is as follow:

Q: A 90% confidence interval for a population mean is (10, 20). What is the margin of error of the…

A: Given  alpha=0.10,  CI=(10,20)

Q: For the same sample statistics, which level of confidence would produce the widest confidence…

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Q: What is the confidence interval estimate of the population mean u?

A: From the given sample data :  The sample size is , n=10 The sample mean is , X¯=∑Xn=1742/10=174.2…

Q: What is meant by saying that a 1−α confidence interval is a. exact? b. approximately correct?

A: a) 1−α confidence interval is Exact means that the probability that the unknown value of population…

Q: What is the formula for CONFIDENCE INTERVAL (CI) FOR μ1 – μ2 (TWO INDEPENDENT SAMPLES)?

A: From the given information, consider two independent samples drawn randomly with sample sizes n1 and…

Q: What two conditions will result in the use of the student-t distribution when constructing a…

A: Confidence interval for mean: When the sample size is large (n>30) and population variance (or…

Q: What will happen to the precision of a confidence interval if the variability of a sample gets…

A: Farmula  Length of Confidence interval=2xZcxσ/√n

Q: State the assumptions for computing a confidence interval on the difference between means?

A: Solution: Suppose that there are two populations. In order to estimate the difference between the…