STA 2023 Lecture Notes - Lecture 14: Normal Distribution, Standard Deviation
Document Summary
Step 1: draw a normal curve and shade the desired area. Step 2: convert the values of x to z-scores using z=x-mean/standard deviation. Step 3: draw a standard normal curve and shade the desired area. Step 4: find the area under the standard normal curve. This area is equal to the area under the normal curve. A survey indicates that for each trip to the supermarket, a shopper spends an average of 45 minutes with a standard deviation of 12 minutes in the store. The lengths of time spent in the store are normally distributed and are represented by the variable x. A shopper enters the store: find the probability that the shopper will spend more than 30 minutes in the store. Press enter: find the probability that the shopper will spend between 15 and 60 minutes in the store. Step 1: draw the normal curve and shade the desired area.
