assume that all criteria for constructing the confidence int

assume that all criteria for constructing the confidence intervals were met.

A container of motor oil is supposed to contain 1000 ML of oil. A quality control engineer is concerned about the variability of the filling process. She randomly selects 10 containers. The number of ML in each container is given below:

983.6                     1038.9                   995.2                     989.2                     980.5

999.6                     974.5                     1035.8                   945.7                     983.3

Construct a 95% confidence interval for the population standard deviation. Interpret the meaning of this interval.

Please give detailed information

Solution

mean=992.63

sd=1000

z-value for 95% is 1.96

so the formula is

C.I=x+z*sd/sqrt(n)

C.I=992.6+(1.96)*1000/sqrt(10)

C.I=1612.407