Suppose we want a 95% confidence interval for the average amount spent on books by freshmen in their first year at college. The amount spent has a normal distribution with standard deviation $22. (a) How large should the sample be if the margin of error is to be less than $2? Use at least 3 decimal places in your critical value. ANSWER:

Q: The weights of men in a particular age group have mean ? = 176 pounds and standard deviation ? = 36…

A: The random variable X follows normal distribution. We have to find the standard error of the mean…

Q: 4. There were 17 sophomores who took this course with a mean score of 66.5 and a standard deviation…

A: (a)   State the hypotheses.   Obtain the degrees of freedom.   The degrees of freedom formula for…

Q: After giving grade to a quiz Engr. Cruz announced to the class the mean score was 68 points with the…

A: Given that After giving grade to a quiz Engr. Cruz announced to the class the mean score was 68…

Q: an IQ test is designed so that the mean is 100 and the standard deviation is 16 for the population…

A: Given that, μ=100σ=16Margin of error=E=4α=0.1The critical value at α=0.1 is zα/2=1.645

Q: If a population has a standard deviation of 16, what is the minimum number of samples that need to…

A: Given,standard deviation (σ)=16margin of error (E)=2α=1-0.88=0.12α2=0.06Z0.06 =1.5548

Q: Suppose that grade point averages of undergraduate students at one university have a bell-shaped…

A: Given, grade point averages of undergraduate students at one university have a bell-shaped…

Q: If a set of data is normally distributed with a mean of 50 and a standard deviation of 5, a z-score…

A:

Q: If the standard error (σX) of the mean distribution is 10 and the sample size is 25, then what is…

A: Given information Standard error of the mean distribution = 10 Sample size = 25

Q: 2. Researchers found that students who binge drink spend a mean time of 4.9 hours drinking during…

A:

Q: he mg of nicotine in menthol cigarettes is normally distributed and a sample of 25 menthol…

A: Given: s= 0.24 n = 25 The variance can be calculated as: s2=0.242≃0.058 The degrees of freedom will…

Q: An IQ test is designed so that the mean is 100 and the standard deviation is 12 for the population…

A: Givenstandard deviation(σ)=12Marign of error(E)=7c=99%α=1-0.99=0.01α2=0.005zα2=z0.005=2.5758   (from…

Q: What is the R script for this problem? Select five simple random samples of 10, 25, and 50 male…

A: This script will:Load the provided dataset containing mosquitofish lengths.Define a function…

Q: Two companies manufacture a rubber material intended for use in an automotive  application. The part…

A:

Q: An IQ test is designed so that the mean is 100 and the standard deviation is 22 for the population…

A:

Q: A Data has a mean of 50 and a standard deviation of 6. (a) What are the mean and standard deviation…

A: Central Limit Theorem for mean: If a random sample of size N is taken from a population having mean…

Q: 7) For a normally distributed population with a mean of 35 and a standard deviation of 10 find P(X…

A: Solution:From the given information, normal distribution with population mean as 35 and standard…

Q: Suppose that grade point averages of undergraduate students at one university have a bell-shaped…

A: According to the given information, we have Mean = 2.55 Standard deviation = 0.43 Given that the…

Q: If the population standard deviation is 17, at 95% CI, sample mean is within 5 of the population…

A:

Q: Suppose IQ scores of students at Bradley follow a normal distribution with a mean of 103 and a…

A: Calculate the IQ score for the top 2.5% of all IQ's at this college.

Q: Two phone batteries are to be tested for how they last (i.e., lifetime). Phone battery A has a…

A: Phone battery A has a lifetime is normally distributed with mean 4.1 and standard deviation…

Q: What is the standard error of the mean for a sample that has n=53 people and comes from a population…

A: It is given that n = 53s = 11

Q: When we are calculating variance (or standard deviation) for a sample and intend to use it as an…

A: Given information: s=∑xi-x¯2N-1s2=∑xi-x¯2N-1

Q: Find the standard error of the sample mean such that we have 50 random samples with mean 30 and…

A: Number of random samples,  Mean=30 Standard deviation,

Q: Suppose that the amount of time per day that American adults spend on their mobile devices is…

A: From the provided information, Mean (µ) = 229 Standard deviation (σ) = 57

Q: level of nitrogen oxides (NOX) in the exhaust of a particular car model varies with mean 0.9 grams…

A: Formula : σ_x̄ = σ/√n

Q: The SAT scores (X) are normally distributed with mean 152 and standard deviation 43, If 10 SAT…

A: Answer: From the given data, Sample size(n) = 10 Mean (μ) = 152 Standard deviation(σ) = 43 X follows…

Q: If all 24 samples from a population produce the same age x = 20, what are the sample meanµ and the…

A: All 24 samples from a population produce the same age x=20. That is each xi=20 then

Q: If I have the variance of 36 and the standard deviation of 6, how do I calculate the range?

A: From the provided information, Variance (σ2) = 36 Standard deviation (σ) = 6

Q: What would someone's approximate  stanine score be if their raw score was 79 from a group with a raw…

A: Given that Mean = 85 SD = 5 And raw score X = 79

Q: A firm purchases a very large quantity of off-cutts metals and wishes to know the average weight of…

A:

Q: The waiting time for patients at a health clinic follows a normal distribution with a mean of 15…

A: We have to perform Z test for mean.

Q: If the standard error of the mean is σx̅ = 3 and the sample size is n = 64, then the population…

A:

Q: If random samples of the given sizes are drawn from populations with the given proportions, find the…

A:

Q: SAT scores are distributed with a mean of 1,500 and a standard deviation of 300. You are interested…

A: State the given values. The z value at 95% confidence level is 1.96.

Q: A population is normally distributed with a mean of 51 and a standard deviation of 12. (a) What is…

A: (a) Obtain the mean of the sampling distribution for the given population. The mean of the sampling…

Q: Suppose you take a sample of size 60 from a Normal distribution with  population mean (mu) 412 and…

A:

Q: 1. If the standard deviation for a set of numbers equals 15, what is the variance for the same…

A: Hey there! Thank you for posting the question. Since there are multiple questions posted, we will…

Q: Suppose that you are interested in the number of people in each household in the U.S. Your sample…

A: C. It should be narrower than the 95% CI. Explanation:99% intervalz= 99%= 2.576n=10x̄=2.5σ=1.2…

Q: The weights of men in a particular age group have mean ? = 174 pounds and standard deviation ? = 32…

A:

Q: Suppose we know that the mean score among the population of college students taking the GMAT test is…

A: Here Given  Sample size=n=100 Population Mean=1000=μ Population sd=σ=1200 Here SAMPLE SIZE IS…

Q: Do the mean weights of male college freshmen and male college seniors differ? There are arguments…

A: Note: Hi there! Thank you for posting the question. As there are multiple sub parts, according to…

Q: If you wish to run a hypothesis test to see if the mean cholesterol level is more than 200 mg/dL,…

A: Test is that whether mean cholesterol level is more than 200 mg/dL.