The file Confidence Interval Simulation.xlsx generates observations randomly from a normal population. Suppose instead that each observation in column A is exponentially distributed with mean 10.  Unlike a normal distribution, an exponential distribution is very skewed to the right. A value from this distribution can be generated with the formula =−10*LN(RAND()). Rerun the simulation, still with sample size 30, with this exponential distribution. Are 95% confidence intervals still valid? That is, is the percentage in cell H7 approximately equal to 95%, as it should be? Press the F9 key a few times to check this.