The research department of an appliance manufacturing firm has developed a solid-state switch for its blender that the research department claims will reduce appliance returns under the one-year full warranty by 3%-6%. To determine if the claim can be supported, the testing department selects a group of the blenders manufactured with the new switch and a group with the old switch and subjects them to a normal year's worth of wear. Out of 250 blenders tested with the new switch, nine would have been returned. Sixteen would have been returned out of the 250 blenders with the old switch. As the manager of the appliance manufacturing process, use a statistical procedure to verify or refute the research department's claim.

Summarize the problem with the appliance manufacturing firm's blenders.

Propose the statistical inference to use to solve the problem.

Using Excel:

• Develop a flowchart for the proposed statistical inference, including specific steps.
• Compute all statistical calculations using Excel.

Determine if you can verify or refute the research department's claim.