What sample size is necessary such that a 95% confidence interval for the mean, using σ = 3, has a width of ±0.5

Q: Suppose that the population standard deviation of students score is 20. what is the sample size so…

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Q: The Human Resource Department (HRD) of a company developed an aptitude test for screening potential…

A: Solution: Given information: n= 13 Sample size  x=96 Sample meanμ=100 Population means= 5.2 sample…

Q: A sample of 28 adults attending a country fair determined that the mean age was 34, given that the…

A:

Q: How large of a sample is required for a poll to have an error of less than 1.2% at a 90% confidence…

A: Given that  Margin of error =E =1.2%=0.012 90% confidence level.

Q: A quality control manager wants to be sure that the standard deviation of oil containers is below a…

A: Let Xi be the amount of oil in the ith container,i=1,2,...,n.

Q: We are interested in estimating the average amount spent per customer for lunch in a restaurant in…

A: Confidence interval: It is defined as the range which contains the value of a true population…

Q: A random sample of 100 Colorado residents is selected, and it is found that 82% of them have Subaru.…

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Q: A sample of 26 observations is taken from a normal distribution with unknown mean, the sample mean…

A: Answer: From the given data, Sample size(n) = 26 mean (x¯) = 12.6 Standard deviation(σ) = 2.5 95%…

Q: How large of a sample is required for a poll to have an error of less than 1.5% at a 95% confidence…

A: Given:

Q: A sample of 42 observations is taken from a normal population with a standard deviation of 8. The…

A: Answer: From the given data, Sample size(n) = 42 Mean (X¯) = 45 Standard deviation(σ) = 8 99%…

Q: the standard deviation of the 16 observations was 0.95 inches (again, the sample mean was 17.2).…

A: Given :  Standard deviation of the 16 observations was 0.95 inches & the sample mean was 17.2.…

Q: For a sample 1000 app users, the research team reports an average age of 39. If the population…

A: given data  n = 1000 x¯ = 39σ = 9.590% ci, upper bound of ci  = ?

Q: Suppose that the population standard deviation of student scores is 20. What will be the sample size…

A:

Q: The total of individual weights of garbage discarded by 17 households in one week is normally…

A:

Q: rvey is conducted to determine the average weekly hours of exercise for a sample of 50 adults. The…

A: given data, n=50df=n-1=50-1=49x¯=3.2s=1.5CI=0.99α=1-0.99=0.01

Q: The mean IQ score of a sample of 61 students selected from a high school is 93. Suppose the standard…

A: Construct the 99% confidence interval for the population mean The 99% confidence interval for the…

Q: In a random sample of 100 male students the average height is 68.2 with standard deviation 2.5 .…

A: The summary of statistics is, x¯=68.2,s=2.5,n=100 The degree of freedom is, df=n-1  =100-1  =99…

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: A sample of 48 observations is taken from a normal population with a standard deviation of 17. The…

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Q: The total of individual weights of garbage discarded by 15 households in one week is normally…

A: The total of individual weights discarded by 15 households is normally distributed with mean 29.7…

Q: e) Find the critical value used to construct a 80% Confidence Interval for the mean. Only for this…

A: Solution: e. From the given information, the population standard deviation is σ=23.8 is known. The…

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

A:

Q: In the estimation of the population mean, what if given that last year mean is 7.05 and SD is…

A: Confidence Interval provides a range of values for the estimated parameter.

Q: We are interested in estimating the average amount spent per customer for lunch in a restaurant at…

A:

Q: Suppose that the true population standard deviation (this assumption is made only for this question,…

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Q: The pH of rain, measured at a weather station in Michigan, was observed for 39 consecutive rain…

A:

Q: for a sample of 57 that has a mean of 6200 and a standard deviation of 254, calculate the 95%…

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Q: or a sample of 121 that has a mean of 6540 and a standard deviation of 780, calculate the 90%…

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Q: A sample of marine iguanas (n=30) from the Galapagos Islands has an average length of 2.8ft with a…

A: given data n=30df=n-1=30-1=29x¯=2.8S2=0.43s=0.43=0.6557CI=0.95α=1-0.95=0.05

Q: a sample 1000 website users, the research department reports an average age of 39. If the population…

A: GIVEN DATA,n=1000x¯=39σ=9.5CI=0.90α=1-0.90=0.10α/2=0.10/2=0.05we have to find out the upper bound…

Q: A study found that a 95% confidence interval for the mean μ of a particular population was computed…

A: Given, 95% confidence interval 10 ± 4  Sample size  = 1200         To write the conclusion regarding…

Q: A sample of 28 adults attending a country fair determined that the mean age was 33,given that the…

A:

Q: A sample from a normal population is given with mean 54 and the standard deviation 12. Find the…

A: Given : n = 25 x¯=54 S = 12

Q: A sample size of 100 from a population having a standard deviation =8 produced a mean of 40. The 99%…

A: Obtain the 99% confidence interval for the population mean. The 99% confidence interval for the…

Q: Suppose that the population standard deviation of a student's score is 20. Choose a sample size so…

A:

Q: The length of a certain type of fish is normally distributed with mean and standard deviation sigma…

A: The sample size can be calculated as: n=z×σE2 Here, z = desired confidence level E = The allowable…

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.