A coffee manufacturer claims that the mean amount of coffee…
A coffee manufacturer claims that the mean amount of coffee in its 4-ounce jars is 4.1 ounces. A consumer advocate group tests whether or not the true average amount of coffee in the 4-ounce jars differs from 4.1 ounces at the 5% level of significance. Based on a sample of 40 4-ounce jars, they find that the average amount of coffee in 4-ounce jars is 3.9 ounces and the standard deviation is 0.45 ounces. Note: