A consumer products company wants to increase the absorption capacity of a sponge. Based on past data,the average sponge could absorb 3.5 ounces. After the redesign,the absorption amounts of a sample of sponges were (in ounces): 4.1,3.7,3.3,3.5,3.8,3.9,3.6,3.8,4.0,and 3.9. At the 0.01 level of significance,what is the decision rule to test if the new design increased the absorption of the sponge?
A)Reject the null hypothesis if computed t is less than 2.580.
B)Reject the null hypothesis if computed t is greater than 2.821.
C)Reject the null hypothesis if computed z is 1.96 or larger.
D)Reject the null hypothesis if computed t is less than 2.764.

Question

Quizplus · Accepted Answer

At the 0.01 level of significance for a one-tailed test with a sample size less than 30, the t-distribution is used. The critical value of t for a one-tailed test with 9 degrees of freedom (n-1) at the 0.01 level is greater than 2.821.

A Consumer Products Company Wants to Increase the Absorption Capacity