A manufacturer bonds a plastic coating to a metal surface. A random sample of nine observations...

A manufacturer bonds a plastic coating to a metal surface. A random sample of nine observations on the thickness of this coating is taken from a week's output and the thickness (in millimeters) of these observations are shown below. Assuming normality, find a 90% confidence interval for the population variance.

19.1.

21.7

18.7

20.1

21.5

19.5

19.1

20.2

20.3

Solutions

Expert Solution

orchestra answered 1 year ago

Next > < Previous

Related Solutions

Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity...

Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity paint. 0.83 0.87 0.89 1.02 1.09 1.14 1.27 1.29 1.46 1.51 1.60 1.64 1.67 1.70 1.78 1.83 Determine the z percentile associated with each sample observation. (Round your answers to two decimal places.) Sample observation 0.83 0.87 0.89 1.02 1.09 1.14 1.27 1.29 z percentile Sample observation 1.46 1.51 1.60 1.64 1.67 1.70 1.78 1.83 z percentile

Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity...

Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity paint. 0.83 0.86 0.86 1.02 1.08 1.12 1.29 1.31 1.46 1.51 1.60 1.63 1.67 1.69 1.74 1.84 Determine the z percentile associated with each sample observation. (Round your answers to two decimal places.) dont just calculate , please show step by step

Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity...

Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity paint. 0.84 0.89 0.90 1.02 1.08 1.14 1.28 1.31 1.47 1.47 1.60 1.62 1.66 1.73 1.75 1.81 Determine the z percentile associated with each sample observation. (Round your answers to two decimal places.) Sample observation 0.84 0.89 0.90 1.02 1.08 1.14 1.28 1.31 z percentile Sample observation 1.47 1.47 1.60 1.62 1.66 1.73 1.75 1.81 z percentile

Consider the following sample of observations on coating thickness for low-viscosity paint. 0.87 0.88 0.88 1.05...

Consider the following sample of observations on coating thickness for low-viscosity paint. 0.87 0.88 0.88 1.05 1.09 1.14 1.29 1.31 1.46 1.49 1.59 1.62 1.65 1.71 1.76 1.83 Assume that the distribution of coating thickness is normal (a normal probability plot strongly supports this assumption). (c) Calculate a point estimate of the value that separates the largest 10% of all values in the thickness distribution from the remaining 90%. [Hint: Express what you are trying to estimate in terms of...

A random sample of 42 observations is used to estimate the population variance. The sample mean...

A random sample of 42 observations is used to estimate the population variance. The sample mean and sample standard deviation are calculated as 74.5 and 5.6, respectively. Assume that the population is normally distributed. a. Construct the 90% interval estimate for the population variance. (Round intermediate calculations to at least 4 decimal places and final answers to 2 decimal places.) b. Construct the 99% interval estimate for the population variance. (Round intermediate calculations to at least 4 decimal places and...

A random sample of 20 observations is used to estimate the population mean. The sample mean...

A random sample of 20 observations is used to estimate the population mean. The sample mean and the sample standard deviation are calculated as 162.5 and 22.60, respectively. Assume that the population is normally distributed. a. Construct the 99% confidence interval for the population mean. (Round intermediate calculations to at least 4 decimal places. Round "t" value to 3 decimal places and final answers to 2 decimal places.) b. Construct the 95% confidence interval for the population mean. (Round intermediate...

A random sample of 105 observations produced a sample mean of 33. Find the critical and...

A random sample of 105 observations produced a sample mean of 33. Find the critical and observed values of z for the following test of hypothesis using α=0.025. The population standard deviation is known to be 9 and the population distribution is normal. H0: μ=28 versus H1: μ>28. Round your answers to two decimal places. zcritical = zobserved =

A random sample of 100 observations produced a sample mean of 32. Find the critical and...

A random sample of 100 observations produced a sample mean of 32. Find the critical and observed values of z for the following test of hypothesis using α = 0.025 . The population standard deviation is known to be 5 and the population distribution is normal. H 0 : μ = 28 versus H 1 : μ ≠ 28 .

A random sample of 136 observations produced a sample mean of 29. Find the critical and...

A random sample of 136 observations produced a sample mean of 29. Find the critical and observed values of z for the following test of hypothesis using a=0.1. The population standard deviation is known to be 5 and the population distribution is normal. H0: mean = 28 versus H1: mean not equal to 28. Round your answers to two decimal places. zcritical left= zcritical right = zobserved =

A random sample of 29 observations is used to estimate the population mean. The sample mean...

A random sample of 29 observations is used to estimate the population mean. The sample mean and the sample standard deviation are calculated as 130.2 and 29.60, respectively. Assume that the population is normally distributed Construct the 95% confidence interval for the population mean. Construct the 99% confidence interval for the population mean Use your answers to discuss the impact of the confidence level on the width of the interval. As the confidence level increases, the interval becomes wider. As...

Subjects