Every Normal model is defined by its parameters, the mean and the standard deviation. For each model described below, find the missing parameter. As always, start by drawing a picture. a) μ=23,35% above 30;σ= ? b) μ=86,2% below 55;σ= ? c) α=5.3,80% below 80;μ= ? d) σ=15.2,10% above 16.9;μ= ?