anonymous one year ago I'm reading a research article and am having trouble understanding the following.. "Regardless of whether the book was written by a new or established author, being positively reviewed significantly increased sales; a positive review generated between a 32% and 52% increase in demand (no significant difference between coefficients, z = 1.0, p > 0.30)." What does the z here refer to?

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1. jim_thompson5910

z is the standard z-score

2. jim_thompson5910

the way z is often computed is this $\Large z = \frac{x-\mu}{\sigma}$

3. jim_thompson5910

mu is the mean, sigma is the standard deviation