The z score can be calculated by the difference of population and sample mean divided by standard error. Standard error can be calculated as the standard deviation divided by square root of sample size From the given the standard error: SE = 12/sqrt (20) = 2.68 Z = (208 -195)/2.68 = 4.85
Her voice was probably very flexible (keep in mind dancing), her voice was very pretty (keep in mind the twinkle) and her voice probably loses focus really fast (keep in mind wandered)
