Acme Foods wants to make its chips saltier, but it doesn't want to spend more than it has to on salt. A sample of consumers are asked to compare its current chip (saltiness = 100) with saltier versions and to say whether the new version is saltier. On average, sample consumers reliably say the new chip is saltier when its saltiness value is 108, but not when its saltiness value is below 108. Assuming Acme Foods' sample consumers are representative of people in general, which of the following BEST represents the difference threshold for saltiness?

Question

Quizplus · Accepted Answer

The difference threshold, also known as the just noticeable difference (JND), refers to the smallest detectable difference between two stimuli. In this case, the difference threshold for saltiness would be the smallest increase in saltiness that consumers reliably detect. 
Based on the given information, consumers reliably detect a difference in saltiness when the saltiness value is increased by 8 (from 100 to 108). Therefore, the difference threshold for saltiness would be 8%, because it represents the percentage increase in saltiness that consumers can reliably detect.

Acme Foods Wants to Make Its Chips Saltier, but It