Public Policy and Political Science
A technical panel investigating residential smoke alarms recommends that the sound emitted by the device (during a fire) should be at least 85 decibels at 10 feet away. In a random sample of 60 smoke alarms from homes in a large city, the sample mean decibel level (at 10 feet away) was x‾ = 84.88. Assume σ = 5.6.
a. Is there any evidence that the true mean decibel level produced by smoke alarms in this city is less than 85? Use a = 0.01 and compute the p value to draw a conclusion.
b. What is the smallest significance level at which this hypothesis test would be significant?