An IQ test is designed so that the mean is 100 and the standard deviation is 9 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 95 percent confidence that the sample mean is within 2 IQ points of the true mean. Assume that o? = 81 and determine the required sample size.

Q: From sample sizes of 36 adults find the proportion of sample means having values of at least 170.

A: Here Given  Sample size=n=36  Population mean=μ=162 Population SD=σ= 58

Q: Suppose the population values 50 and 80 and that their corresponding z scores are -1 and 2…

A: The z score for the population value of 50 is -1 and the z score for the population value of 80 is…

Q: A company that manufacturers batteries for cell phones wants to estimate the mean number of hours…

A: Given: Standard deviation (σ) = 3.85 Margin of error (E) = 1.5 Confidence level = 95%

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A: Note: According to Bartleby, expert solve only one question and rest can be reposted.

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A: Computation of test statistic value: Sample size is smaller than 30 and the population standard…

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A:

Q: Assume that adults have IQ scores that are normally distributed with a mean of 98.7 and a standard…

A: Given data, μ=98.7σ=16.2P(X<x)=25%x=?

Q: Use the z table to find the value k so that 40% of the scores are greater than k.

A: Normal distribution is widely used in statistics . It is very useful in modern times .

Q: A nutritionist claims that the mean tuna consumption by a person is 3.1 pounds per year. A sample…

A: Solution: Let X be the tuna consumption by a person. From the given information, n=90, x-bar=2.9 and…

Q: Suppose the number of dollars spent per week on groceries is normally distributed. If the population…

A: Given information: Population standard deviation, σ is 7 dollars. Margin of error, E is 3 dollars.…

Q: A psychologist believes that it will take at least an hour for certain disturbed children to learn a…

A:

Q: A sociologist wishes to see whether for a certain group of professional women, the average age at…

A: Given  mu=30.2, n=30, Xbar=28.7, s=2.1, alpha=0.05 Sigma(unknown) test…

Q: If you want to be 99% confident of estimating the population mean to within a sampling error of ±20…

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Q: . A biologist is interested in studying the effect of vitamin supplements on deer mouse body length.…

A:

Q: For a random sample of 40 students, the average statistics midterm score is 73 points (out of a…

A: The sample size is 40, average statistics midterm score is 73 points, and standard deviation is 7.3.

Q: Suppose that 16 samples of pesticide concentrations in plants in Halifax are taken giving a sample…

A: Given,margin of error(E)=2standard deviation(σ)=5.3α=1-0.99=0.01α2=0.005Z0.005=2.58     (from…

Q: For a random sample of 9 women, the average resting pulse rate is x-bar = 76 beats per minute, and…

A:

Q: Assume the average income of workers in jordan equal 400 JD, a sample of 500 workers are taken and…

A: Given: Average income of workers in jordan = 400 Sample size n=500 sampling error is 10. standard…

Q: How many commuters must be randomly selected to estimate the mean driving time of Chicago commuters…

A: Given Information: Confidence level = 90%  Error (e) = 4 minutes Standard Deviation (s) = 12 minutes…

Q: A university dean of students wishes to estimate the average number of hours students wish to spend…

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

Q: If a z-score is equal to −2.05, it is 2.05 standard deviations below the mean. True or False

A: The standardized difference, which measures the difference between a random score (i.e., a value…

Q: The average score of 200 students in a mathematics test is 75 with a standard deviation of 4. Then…

A: Solution-: Given: \mu=75, \sigma=4, n=200 (Number of students) Let, X= The score of students in a…

Q: Assume that adults have IQ scores that are normally distributed with a mean of 95.6 and a standard…

A: Given: x~N(μ,σ)μ=95.6σ=24.3

Q: Assume that adults have IQ scores that are normally distributed with a mean of 100.3 and a standard…

A: Assume that adults have IQ scores that are normally distributed with a mean of 100.3 and a standard…

Q: For a random sample of 9 women, the average resting pulse rate is x̅ = 76 beats per minute, and the…

A: Given: Sample size (n) = 9 Sample mean x¯=76 Sample standard deviation (s) = 5

Q: In the general population, the mean IQ is 100 with a standard deviation of 15. Dr. Robbins wants to…

A: From the provided information, Population mean (µ) = 100 Population standard deviation (σ) = 15

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Q: The population standard deviation for the heights of dogs, in inches, in a city is 5.7 inches. If we…

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Q: A nurse at a local hospital is interested in estimating the birth weight of infants. How large a…

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Q: 2. In a particular normally distributed set of scores, the mean is 65.75 and thestandard deviation…

A: As per the honor code, We’ll answer the first question since the exact one wasn’t specified. Please…

Q: ) Assume that adults have IQ scores that are normally distributed with a mean of 100 and a standard…

A: Let "X" be the IQ score of adults. Find z-value (z): Refer Standard normal table/Z-table, Lookup…

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Q: The average number of moves a person make in his/her lifetime is 12 and the standard deviation is…

A: Given,sample size(n)=25mean(μ)=12standard deviation(σ)=3.5

Q: The 2008 General Social Survey asked a large number of people how much time they spent watching TV…

A: According to the given question, The 2008 General Social Survey asked a large number of people how…

Q: Assume that the SAT test scores are normally distributed with a mean score of 1200 and a…

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Q: The mean number of travel days per year for salespeople employed by three hardware distributors…

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Q: A university dean wishes to estimate the average number of hours that freshmen study each week. The…

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Q: Miss Romero noted that the mean scores of a random sample of 15 Grade 8 students who had taken a…

A: Given: Sample size, n=15 Let PE denote point estimate Sample mean, x¯=80.5sample standard deviation,…

Q: The U.S. Department of Transportation provides the number of miles that residents of the 75 largest…

A: confidence interval is a part of interval estimation. Interval estimation gives the value of the…

Q: A researcher believes that the mean age of medical doctors in a large hospital system is older than…

A:

Q: A nutritionist claims that the mean tuna consumption by a person is 3.3 pounds per year. A sample of…

A: (a) Let μ denotes the population mean tuna consumption. The claim of the test is that the mean tuna…

Q: It is known that the mean is 65 and the standard deviation is 10. There are 30 students in the…

A:

Q: A medical statistician wants to estimate the average weight loss of people who are on a new diet…

A: Solution: Given information: σ= 10  Population standard deviation E= 2 Margin of error C= 0.9=90%…

Q: How large a sample must be taken to be 99% confident that the estimate of the average time of…

A:

Q: A medical statistician wants to estimate the average weight loss of people who are on a new diet…

A: Given Data: ME=4/2=2 σ=8   z-value corresponding to 97% of CI=2.17

Q: In order to set rates, an insurance company is trying to estimate the number of sick days that full-…

A:

Q: The president of a college wants to determine the mean number of units that college students take…

A: From the given information, the population standard deviation is 2.1 units, the confidence level is…

Q: A nutritionist claims that the mean tuna consumption by a person is 3.5 pounds per year. A sample of…

A: (a) Let μ is defined as the population mean tuna consumption by a person. The claim of the test is…

Q: The mean salary of all employees in a company is $3,485, and the standard deviation is $1,870. Find…

A:

Q: How large a sample must be taken to be 99% confident that the estimate of the average time of…

A: