Suppose that the population standard deviation of student scores is 20. What will be the sample size so that the resulting 90% confidence interval for the population mean score has a margin of error no larger than 4?

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

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Q: Suppose we know that a confidence interval is (27,35), with a margin of error of 4. Find the sample…

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Q: Find a 90% confidence interval for the population mean, if the sample size is 58, the sample mean is…

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Q: Suppose you take a sample of size 39 from a Normal distribution with unknown population mean and a…

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Q: Suppose that the amount of time spend by working student weekly is normally distributed with the…

A: Given,   Sample size = 120 Sample mean = 150 Population standard deviation = 25   Since the…

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: f the population standard deviation of AAA batteries (with a polulation mean of 9 hours) is 0.5…

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Q: Suppose you take a sample of size 45 from a Normal distribution with unknown population mean and a…

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Q: Suppose we want a 90% confidence interval for the average amount spent on books by freshmen in their…

A: Given,standard deviation(σ)=19α=1-0.90=0.1α2=0.05z0.05=1.645and margin of error(E)=4

Q: An advertising company wishes to estimate the mean household income for all single working…

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Q: If the sample has standard deviation 2.1, what is a reasonable approximation to the range of this…

A: It is given that the standard deviation of the data is 2.1.

Q: If a school district takes a random sample of 75 Math SAT scores and finds that the average is 433,…

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Q: Suppose we know that a confidence interval for a population mean is (53, 67), with a margin of error…

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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: Suppose a random sample of 100 individuals is taken and that average wage for that sample is $870…

A: It is given that the mean is 870 and the population standard deviation is 300.

Q: From the scores in subject statistics for 8 students, it was found that the mean score is 73 and the…

A: We have given that,  Sample mean (x̄) = 73,  standard deviation (s) = 5.15 and sample size (n) = 8…

Q: If a school district takes a random sample of 75 Math SAT scores and finds that the average is 433,…

A: It is given that the mean is 433 and the population standard deviation is 100.

Q: An automotive manufacturer wants to know the proportion of new car buyers who prefer foreign cars…

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Q: A student conducted a study and reported that the 95% confidence interval for the population mean…

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Q: An analyst is planning to estimate the mean of a quantitative variable using a 95% confidence…

A: Given that, Critical value: Using the z-table, the critical value at 95% confidence level is

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: 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: 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: 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: An investigator computes a 95% confidence interval for a population mean on the basis of a sample of…

A: To find half of width, We need to calculate 4 times the sample Size.

Q: What is the difference in the computation of a confidence interval between cases in which you know…

A: Population standard deviation known: When population standard deviation is known, the z-critical…

Q: It is known that the population mean for the verbal section of the SAT is 500 with a standard…

A: From the provided information, Sample size (n) = 400 Sample mean (x̅) = 511 Population standard…

Q: The sample size needed to estimate a population mean within 2 units with a 95% confidence when the…

A: Given,σ=8E=2Zc at 95% confidence is Zc=1.96n=?

Q: Assume that you took a sample and calculated the sample mean as 100.you then calculated the lower…

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Q: Suppose that the amount of time teenagers spend playing computer games per week is normally…

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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: Suppose we know that a confidence interval for a population proportion is (0.572, 0.662), with a…

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Q: Suppose you observe 62 data points from a distribution with standard deviation 2.1, and you…

A: Given, n=62 data points standard deviation SD= 2.1, calculated a 92% two-sided confidence interval…

Q: Suppose a drug for stomach discomfort is tested on 50 subjects, and the mean time for it to take…

A: To find the confidence interval we will use z distribution because the population standard deviation…

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: Now suppose of interest is to estimate the mean number of children attending all 2017 Veterans Day…

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Q: Suppose that a random sample of 11 scores from a population of test scores is to be used to estimate…

A: Chebyshev's rule and empirical rule and related to the proportion of data that falls with different…

Q: The national fire protection association reported that house fires in the United States result in…

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Q: Construct a 95% confidence interval for the population standard deviation σ if a sample of size 10…

A: Solution

Q: Suppose the prices for the iphone 12 are normally distributed with an unknown population mean and a…

A: The sample mean is 850 and the population standard deviation is 75.

Q: Suppose average pizza delivery times are normally distributed with an unknown population mean and a…

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Q: Suppose the scale readings are normally distributed with an unknown mean and standard deviation of…

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Q: Suppose you compute a confidence interval with a sample size of 37. What will happen to the…

A: If the sample size increases from 37 to 70 then, the margin of error of the confidence interval…

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: Construct a 99% confidence interval for the population standard deviation σ if a sample of size 11…

A: Confidence Interval: A confidence interval, in statistics, refers to the probability that a…

Q: suppose that in sampling for the population proportion, it is found that 20 out of 100 items are…

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Q: Suppose a sample of 9 customers spends an average of $200 with a standard deviation $20 what is a…

A: Solution:   Given that, Mean x̄ = 200 Sample size n = 9 Standard deviation s = 20

Q: Suppose that based on a random sample, a 95% confidence interval for the mean hours slept (per day)…

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Q: Construct a 99% confidence interval for the population standard deviation σ if a sample of size 8…

A: Confidence interval: The (1-α) % confidence interval for population standard deviation is given by:

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.