Consider the process at Kellogg’s that files boxes of Frosted Flakes.
The target weight of sugary corn flakes per box is set at 18 ounces. Due to the nature of this process, we expect some slight variation in the weights of the boxes. Suppose that historically, when the process was performing as designed, the standard deviation of the weights was 0.15 ounces. To verify that the filling process is currently operating with this variation, 18 randomly selected boxes were weighed on a precision scale and were found to have the following weights.
18.0 18.1 18.0 17.8 18.1 18.1
18.0 18.0 18.0 18.0 17.9 18.0
18.1 17.8 17.8 18.0 17.9 18.0
Using alpha = 0.10, determine if the filing process still has a standard deviation equal to 0.15 ounces.