1. A simple random sample of size 50 is drawn from a population that has a standard deviation of 24. a) Find the margin of error for a 90% confidence interval for the population mean. b) If the sample size had been 40 would the margin of error have been larger or smaller. Explain why.

Q: 2. Construct a 95% confidence interval for the standard deviation of math scores of students maj in…

A: Given Data for constructing the Confidence interval : Sample variance = s2 = 572 = 3249 We need to…

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

A:

Q: 3. Compute for the sample size if the margin of error is 12, with a sample standard deviation of 35…

A: The z-critical value for a 95% confidence interval is calculated using the excel formula…

Q: What is the smallest sample size that guarantees that the margin of error is less than 6 when…

A:

Q: Suppose, according to a 1990 demographic report, the average U. S. household spends $90 per day.…

A: Sample mean = $84.5.Sample standard deviation, s is $14.5.The sample size, n is 30.

Q: Find the sample size required to make to be 3 inches. 95% confidence interval estimate of the mean…

A:

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: Suppose a sample of 30 Statistics students are given an IQ test. If the sample has a standard…

A: Given n=30, sample standard deviations s=12.23

Q: A sample of 49 managers reveals a sample mean of $45,420. The standard deviation of the samp is…

A: As the population standard deviation is not known, we will use t-distribution. The number of degrees…

Q: Suppose the mean wait-time for a telephone reservation agent at a large airline is 42 seconds. A…

A: Given : Suppose the mean wait time for a telephone reservation agent at a large airline is 42…

Q: 6. A research article reported that for a random sample of 850 meal purchases made at fast food…

A: We have to perform left tailed test for the difference in means and since sample size is large…

Q: 9.2 An electrical firm manufactures light bulbs that have a length of life that is approximately…

A:

Q: 8. A sociologist focusing on popular culture and media believes that the average number of hours per…

A: Given : Mean : d = X1 - X2    = 1 σ1 = 2.3σ2 = 2.5 σd = σ12n1+σ22n2     = 2.3250+2.5250= 0.2308=…

Q: 3. Compute for the sample size needed if the margin of error is 85, with sample standard deviation…

A: We hava given that,  Margin of error (E) = 85 and sample standard deviation (s)= 215 and…

Q: Nationally, patients who go to the emergency room wait an average of 7 hours to be admitted into the…

A: Denote μ as the true mean waiting time.

Q: Nationally, patients who go to the emergency room wait an average of 5 hours to be admitted into the…

A: Given: μ0=5 hours.n=11x¯=2.7 hours s=2.9 hoursα=0.05

Q: 4. A random sample of 100 public school teachers in a particular state has a mean salary of $31,578.…

A: Given, a random sample of 100 public school teachers in a particular statehas a mean salary of…

Q: a. What is the standard deviation of sampling distribution of the sample mean for Machine 1? b. Find…

A: Given Data : a)  For Machine 1 : Count, N: 9 Sum, Σx : 144.1 Mean, x̄2 =Σx/N  16.0111…

Q: 6. A food snack manufacturer samples 7 bags of pretzels off the assembly line and weighs their…

A: The confidence interval measure the range where the true population parameter exist. If the…

Q: 1. Construct a 99% confidence interval for a sample mean of 67.5, sample standard deviation of 8.3…

A: Given x¯=67.5s=8.3n=7

Q: Nationally, patients who go to the emergency room wait an average of 7 hours to be admitted into the…

A: Given information- Population mean, μ = 7 hours Sample size, n = 10 Sample mean, x-bar = 6.2 hours…

Q: Determine the sample size necessary to construct a 85% confidence interval with an error of 0.07 if…

A: Given,margin of error (E)=0.07sample proportion…

Q: Construct a 90​% confidence interval for the population standard deviation σ at Bank B.

A: The descriptive analysis is conducted using EXCEL. The software procedure is given below: Enter the…

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

A:

Q: If the manager of a bottled water distributor wants to​ estimate, with 90% ​confidence, the mean…

A: Determine the sample size n needed. Here, confidence level is 0.90.   Use EXCEL Procedure for…

Q: Determine the margin of error for an 80% confidence interval to estimate the population mean with…

A: Given that  Confidence level (C) = 80%  Population standard deviation (σ) = 48   We know that…

Q: What sample size is needed to estimate a population mean within t 70 of the true mean value using a…

A: According to the provided information, Population standard deviation (σ) = 140.625 Confidence level…

Q: 2) Use the given data to find the minimum sample size required to estimate the population…

A:

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: A sample of 14 commuters in Chicago showed the average of the commuting times was 33.2 minutes. If…

A:

Q: 2.The administration at a college wishes to estimate, the proportion of all its entering freshmen…

A: Given;margin of error(E) = 4population standard deviation(σ)= 1.3for confidence level 95%,…

Q: 2. the weights of baby kangaroos are known to have a mean of 125 pounds and a standard deviation of…

A:

Q: Suppose an economist wishes to estimate the mean commute time of workers in Westchester County. The…

A: Given, Sample size n = 31Sample mean x¯ = 31.2Sample standard deviation s = 12.1

Q: 3. Another engineer studies the strength of cables, which has a known population standard deviation…

A: Here we need to obtain the minimum sample size required to obtain a 97% confidence interval.

Q: 1. A pharmaceutical company says that the efficacy rate of their medicine is 90% and the standard…

A:

Q: 2. Construct a 90%, 95%, and 99% confidence interval of the mean weight of fresh oranges if 100…

A: Given : Mean , μ = 180 gm Standard deviation, σ = 30 gm sample size, n = 100 a) Confidence Level =…

Q: Find the error bound for an unknown population mean or the margin of error that corresponds to a 85%…

A: Find the error bound for an unknown population mean or the margin of error that corresponds to a 85%…

Q: 2) Wilson Electronics claims that their new line of Plasma TVs will last for 60, 000 hours. A…

A: Obtain the margin of error for the 95% confidence interval. The formula for the margin of error is,…

Q: ne hundred (900) high school freshmen were randomly selected for a national survey. Among survey…

A: Given data,Mean x=2.7sd     σ=0.4n=900What is the margin of error at 95% confidence level?

Q: 2. Given a random sample with size 39 taken from a normally distributed population or 200 members,…

A: Given : n= 39 x¯=66 σ=11

Q: 13. What is the minimum sample size needed to estimate a population mean within 1 inch at the 98%…

A: 13) Given Information: Confidence level = 98% = 0.98 Margin of error E=1 inch Population standard…

Q: 1) An electronic manufacturer produces lampshades with a life span of approximately normally…

A: Given that   x̄ = 835 ,  ? = 35 , n = 50 Note: According to bartleby experts question answers…

Q: What is the minimum required sample size to make a 96% confidence interval for a population mean if…

A: Margin of error=E=2 Standard deviation=σ=12 96% confidence interval  E=Zc×σ/√n n=sample size

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

A:

Q: 9. Find the minimum sample size needed to be within a margin of error of 2% of the population…

A:

Q: 3. A production engineer claims that the time a trained worker should be able to assemble a certain…

A: The following information has been given: Hypothesized mean μ0=12. Sample mean x¯=12.75. Sample size…

Q: Suppose the mean wait-time for a telephone reservation agent at a large airline is 42 seconds. A…

A: Given: sample size =n=250 sample mean=x=41.3 standard deviation=s=4.2 significance level=α=0.05

Q: What would be the mean of the sampling distribution of all possible sample means obtained from this…

A: Given: μ=5σ=4

Q: Suppose that for a random sample of 200 firms that revalued their fixed assets, the mean ratio of…

A: Given, n1=200 x-1=0.5170 S1=0.148 n2=400 x-2=0.489 S2=0.158 c=99%=0.99

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: