The lower graph shows the beta curve corresponding to a hypotheses test where H0: μ=1 is tested against H1: μ≠1. The upper graph shows the distribution of the sample means for a given population mean. The two red lines in this graphs shows the lower and upper critical values, i.e., when the sample mean is between these two lines we fail to reject H0. The blue line shows the location of the population mean. The height of the beta curve at a given population mean (location of the blue line) is equal to the area between the two red lines (the probability of failing to reject H0 when H0 is false).