Obesity is defined as a body mass index (BMI) of 30 kg/m2 or more. A 95% confidence interval for the percentage of U.S. adults aged 20 years and over who were obese was found to be 20.26% to 29.8%. What was the sample size?

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: How large a sample should be selected to provide a 90% confidence interval with a margin of error of…

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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…

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Q: Given that the 95% confidence interval estimate of the proportion of water specimens that contain…

A: Given  95% CI for population proportion (p) (0.529,0.627)

Q: When calculating the confidence interval for a population mean, which distribution is used?

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

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Q: We would like to know: "What percentage of college students drink alcohol every day?" In a random…

A: Given that, N=500 X=75

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Q: Find the value of ta for a 99% confidence interval when sample size is 30 2

A: Note: Since you have asked multiple question, we will solve the first question for you as per…

Q: Determine the sample size needed to construct a 95% confidence interval for the population mean, μ,…

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Q: Find the 95% confidence interval for the mean score of all such subjects. Round to one decimal…

A: Given : n=27 , X-bar=76.2  , s=21.4  , α=0.05 Since , the population standard deviation (σ) is…

Q: Is the difference between the two indicators significant at the 95% confidence level?

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Q: The mean for the verbal component of the SAT is reported as 500, with a standard deviation of 100. A…

A: It is given that the sample mean is 498 and the population standard deviation is 100.

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

A: Confidence interval:

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A: According to the provided information, sample size (N)=40 number of favorable cases (X) = 26 The…

Q: What is the t-value for a 95% confidence interval given that the sample size is 16? Write the exact…

A: Given: confidence level =95%  Sample size n=16  Then degree of freedom for t-test is =n-1  To find…

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A: Given,   N Average Standard deviation Adults 75 1.8 0.6 Teenagers 75 1.3 0.3

Q: Find the critical tscore to three decimal places when the Confidence Level is 90% and the sample…

A: Given ,sample size (n)=43degrees of freedom(d.f)=n-1=43-1=42α=1-0.90=0.1α2 =0.05

Q: What is the effect of sample size on the width of a confidence interval?

A: If the sample size is increased, then the corresponding margin of error is decreased. Hence, the…

Q: Find the 98% confidence interval for the difference between the means of the two populations

A: Given that sample size n = 18 Mean difference = 22.9 And SD sd = 2.2 The critical value of t at (n -…

Q: Find the critical value, t c,  used for a 95% confidence interval for the mean with a sample size of…

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Q: 1. A poll of 2,500 people shows that 50% approve of a smoking ban in bars and restaurants. What is…

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Q: What value of tn-1 would be used to construct a 99% confidence interval for the mean with a sample…

A: Givenconfidence level(c)=99%sample size(n)=17

Q: How large a sample should be selected to provide a 95% confidence interval with a margin of error of…

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Q: Find the smallest sample size needed to estimate the population proportion for a margin of error of…

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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 the prevalence ratio for the study above equaled 1.63, and the 95% confidence interval (CI) was…

A: A Confidence interval for the mean is a way of estimating the true population mean. Instead of a…

Q: It is believed that slightly over 50% of Americans own pets. A 95% confidence interval for the…

A: Confidence Interval: The form of the confidence interval is, CI = Point estimate ± Margin of error…

Q: If a sample has 20 observations and a 90% confidence estimate for μ is needed, the appropriate…

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Q: for a sample of 150 that has a mean of 6540 and a standard deviation of .89, calculate the 95%…

A: It is given that mean and standard deviation are 6,540 and 0.89, respectively.

Q: How large a sample should be used to provide a 95% confidence interval with a margin of error of 4,…

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Q: For a given sample, a 50% confidence terval for the population mean is narrower than a 90%…

A: For  a given sample size and population standard deviation, the interval estimation of the…

Q: How large a sample should be selected to provide a 99% confidence interval with a margin of error of…

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

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Q: Your analysis of the raw data indicates that 16 of the 30 students reported driving no more than 20…

A: From the given information, let X be the number of students reported no more than 20 miles per day.…

Q: A wider confidence interval gives a greater level of confidence than a narrower one (when working…

A: When we increase the confidence level then confidence interval become wider.

Q: Would represent a 90% confidence interval for the average highway mileage of all Smart Cars?

A: we need to find the confidence interval of the mean GIVEN mean=47 S.D=5 n=15

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: Suppose a 90 percent confidence interval to estimate a population proportion was calculated from a…

A: The confidence interval for proportion can be calculated as follows:

Q: (a) Does the size of the orifice affect the mean percentage of radon released? Use a =0.05. (b) Find…

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Q: Two types of flares are tested and their burning times are recorded. The summary statistics are…

A: Note: Hey there! Thank you for posting the question. For the calculation we are considering x1 as…

Q: What is the t-value for a 90% confidence interval given that the sample size is 26? Write the exact…

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

A: Incomplete