To determine the effect of word-of-mouth marketing, a compan…

To determine the effect of word-of-mouth marketing, a company surveys 20 customers with the question – How likely is it you would recommend our product to a friend? According to the result, 8 of the surveyed customers are promoters, 2 are detractors, and 10 are passives. What is the Net Promoter Score (NPS) for the company based on this result?