A janitorial service wants to estimate the amount of time it takes to change a light bulb. A random sample of 100 light bulb change jobs yields a mean of 22 minutes and a standard deviation of 5 minutes. The 95% confidence interval for the average time it takes to replace a light bulb is (20.1775 , 23.8225) O (21.902 , 22.098) O (21.02 , 22.98) (12.2 , 31.8)

Q: The mean replacement time for a random sample of 12 microwave ovens is 8.6 years with a standard…

A: The sample standard deviation is 2.3 years.

Q: Find a 90%confidence intervalfor thế populadofn stan

A: (1-α)100% confidence interval for σ2 is                                                        First…

Q: A sample of 20 cans of tomato juice showed a standard deviation of .4 ounces. A 95% confidence…

A: Given : Sample size (n)=20 Sample standard deviation (s)=0.4 Confidence interval(C.I)=95% α=0.05

Q: Calculate a 95% upper confidence bound for the mean of a normally distributed population using the…

A: given data  x¯ = 39316n = 14σ= 3276normal distribution 95% upper confidence bound = ?

Q: A 95% confidence interval for the mean hours freshmen spent on social media per day was calculated…

A: Solution: From the given information, the 95% confidence interval for the mean hours freshmen spent…

Q: Find a 95% confidence interval for a mean, µ, where n = 324, x̄ = 2.7, s = .91, and se = .06.

A: Given: n = 324, x̄ = 2.7, s = .91, se = .06.

Q: A simple random sample of 50 has been collected from a population for which it is known that s =…

A: It is given that sample mean is 230.0 and the standard deviation is 10.0.

Q: A report said that the average blood pressure is  130.71  for a sample of  37  white males aged  35…

A:

Q: A 95% confidence interval for the mean was computed with a sample of size 90 to be (16,22). a. What…

A:

Q: A study found the temperature of 125 randomly selected healthy adults averaged 98.25 F with a…

A: It is given that sample mean is 98.25 and standard deviation is 0.733.

Q: Construct a 95% confidence interval for the population mean, μ. Assume the population has a normal…

A:

Q: A random sample of 100 observations produced a mean x̅ =38.5 and a standard deviation of 3.2. find a…

A: Given information Sample size(n) = 100 Sample mean x̅ =38.5 Sample standard deviation = 3.2…

Q: A sample of 64 was taken from a population, with the mean of the sample being 25 and the standard…

A: It is given that  Sample mean = 25 Sample standard deviation = 2 Sample size = 64 Confidence level =…

Q: A study of 100 apple trees showed that the average number of apples per tree was 2000.  The standard…

A:

Q: A study of 64 bolts of carpet showed that their average length was 75 yards. The standard deviation…

A:

Q: A group of 10 foot surgery patients had a mean weight of 240 pounds. The sample standard deviation…

A:

Q: The manager of a grocery store has taken a random sample of 100 customers. The average length of…

A: Since you have asked multiple question, we will solve the first question for you. If you want any…

Q: A simple random sample of 100 observations was taken from a large population. The sample mean and…

A: According to the given information in this question We need to find standard error

Q: Find a 99% confidence interval for μ.

A: The sample size is n = 7 Sample mean = 46.14 Sample SD s = 1.19 At 99% confidence level and df = (n…

Q: A study of 81 bolts of carpet showed that their average length was 77.5 yards. The standard…

A:

Q: A study of 96 bolts of carpet showed that their average length was 77.5 yards. The standard…

A: GivenMean(x)=77.5sample size(n)=96standard deviation(s)=1.6α=1-0.99=0.01α2=0.005zα2=z0.05=2.58

Q: random sample of 36 people in Edirne city was asked how much their monthly income was. The sample…

A: Given: Sample size (n) = 36 Sample standard deviation (s) = 1200 Sample mean x¯=16000 Confidence…

Q: Find the 90% confidence interval for the standard deviation of the lengths of pipes if a sample of…

A: given data s = 10.2 n = 22 90% CI for σ = ? α = 1 - 0.90 = 0.10df = n - 1 = 21χ2L = χ21-α2,n-1…

Q: A random sample of 100 is taken from a population. The sample is found to have a mean of 76.0 and…

A:

Q: A sociologist found that in a random sample of 50 retired men, the average number of jobs they had…

A: Solution: Let X be the random variable defined as the number of jobs a man had during his lifetime…

Q: A study of 96 bolts of carpet showed that their average length was 77.5 yards. The standard…

A:

Q: Find the 95% confidence interval for the variance and standard deviation of the heights of maple…

A: Construct the 95% confidence interval for the variance. Obtain the critical values. The standard…

Q: Find the 95% confidence interval for the variance and standard deviation for the time it takes a…

A: given data   sample size(n) = 21 sample standard deviation(s)  = 5.2construct 95 % ci for σ2 and σ .…

Q: Find the 90% confidence interval for the variance and standard deviation of the ages of students at…

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

Q: A random sample of n =18 data from a normal distrinution with unknown variancex= 25.1 and s=3. 24.…

A: Givensample size(n)=18Mean(x)=25.1Variance(s2)=3.24standard deviation(s)=3.24=1.8

Q: The time needed for college students to complete a certain paper-and-pencil maze follows a normal…

A: Given, Sample size = 20 Sample mean = 30.2 Population standard deviation = 2.9   Under the claim,…

Q: A sample of 64 is taken from a population, with the mean of the sample being 119 and the standard…

A: Option B is correct (113, 125)