Question

The Crown Bottling Company has just installed a new bottling process that will fill 16-ounce bottles of the popular Crown Classic Cola soft drink. Both overfilling and underfilling bottles are undesirable: Underfilling leads to customer complaints and overfilling costs the company considerable money. In order to verify that the filler is set up correctly, the company wishes to see whether the mean bottle fill, μ, is close to the target fill of 16 ounces. To this end, a random sample of 34 filled bottles is selected from the output of a test filler run. If the sample results cast a substantial amount of doubt on the hypothesis that the mean bottle fill is the desired 16 ounces, then the filler’s initial setup will be readjusted. The sample mean is 16. (b) Suppose that Crown Bottling Company decides to use a level of significance of α = 0.01, and suppose a random sample of 34 bottle fills is obtained from a test run of the filler. For each of the following four sample means— x¯ = 16.06, x¯ = 15.97, x¯ = 16.02, and x¯ = 15.91 — determine whether the filler’s initial setup should be readjusted. In each case, use a critical value, a p-value, and a confidence interval. Assume that σ equals .1. (Round your z to 2 decimal places and p-value to 4 decimal places and CI to 3 decimal places.) What are the z values, p values, and CI for each one?

Answer 1

We are given with all the statistics for a z-test. We will find the test statistic using the given information. The p-value is calculated with the help of z-table for a particular z value. The 99% confidence interval can be calculated with the help of the particular sample mean.

Since in all the four cases, the null hypothesis is accepted, hence, the filler will not be readjusted.