“Statistical Analysis of the Effectiveness of a New Bimetallic Thermal Sensor in Reducing Appliance Returns”

Please see the attached. 
The research department of an appliance
manufacturing firm has developed a new bimetallic thermal sensor for its
toaster. The new bimetallic thermal sensor can sense the temperature of the
bread and move the lever arm to activate the switch. The research department
claims that the new bimetallic thermal sensor will reduce appliance returns
under the one-year full warranty by 2%-6%. To determine if the claim can be
supported, the testing department selects a group of the toasters manufactured
with the new bimetallic thermal sensor and a group with the old thermal sensor
and subjects them to a normal year’s worth of wear. Out of 250 toasters tested
with the new bimetallic thermal sensor, 8 would have been returned. Seventeen
would have been returned out of the 250 toasters with the old thermal sensor.
As the manager of the appliance manufacturing process, use a statistical
procedure to verify or refute the research department’s claim.