Suppose that samples of size n 25 are selected at random fr

Suppose that samples of size n = 25 are selected at random from a normal population with mean 100 and standard deviation 10. What is the probability that the sample mean falls in the interval from mu x- 2 sigma x and mu x + 2 sigma x

Solution

Answer is 0.9544 without doing any calculations. This comes directly from empirical rule that 95% of values are withn 2 standard deivaiton of mean for normal distribution. Here the \"values\" are sample means.