新GRE数学题~OG上的 不懂 求解 A list of numbers has a mean of 8 and a standard deviation of 2.5. If x is a number in the list that is 2 standard deviations above the mean, what is the value of x? Answer is 13 麻烦用中文解释一下 OG上的英文解释看的不是很清楚~~
没有理解成乘法 这道题里是加法 "that is 2 standard deviation above the mean" is means that 2.5+2.5 which is equal to two times of standard deviation.他的意思可以是:是standard deviation的两倍