According to New Scientist (January 2, 2012), a new thermal imaging camera that
ID: 3151628 • Letter: A
Question
According to New Scientist (January 2, 2012), a new thermal imaging camera that detects small temperature changes is now being used as a polygraph device. The United State Department of Defense Polygraph Institute (DDPI) claims that the camera can detect liars correctly 75% of the time by monitoring the temperatures of their faces.
A). Set up the null and alternative hypotheses for testing the claim made by the DDPI. Be sure to define the parameter used in your hypotheses.
B). Determine what type I and type II errors are for your hypothesis test.
C) Give two possible strategies in order to improve the power of this test?
D) If the level of significance is prespecified to be 0.05, give the reject region of this test. Assume that sample size is large enough for this test.
Explanation / Answer
According to New Scientist (January 2, 2012), a new thermal imaging camera that detects small temperature changes is now being used as a polygraph device. The United State Department of Defense Polygraph Institute (DDPI) claims that the camera can detect liars correctly 75% of the time by monitoring the temperatures of their faces.
a) Ho : p = 0.75
H1 : p is different form 0.75
b) Type I error will be that we say that the proportion of detect liars is not 75% when in fact is 75%
Type II error will be that we say the proportion of detect liars is 75% when in fact is not 75%