still because Exponential's drop quickly enough there's not a lot of probability mass out in the in the faraway parts the normalization constant upfront that's just you know you do some calculus and you find out that to make sure that this quantity here to make sure it integrates the one you need to put upfront 1 over Sigma of 1 over square root 2 pi ok so what are some properties of gaussians well this is integrate to 1 so we know that this thing integrates to 1 the expected value of your variable X is expected value is you integrate over all