Given: The average number of strokes for a tool is 45,000. The standard deviation is 2,500 strokes. A punch has a total of 25 mm that can be ground off before it is no longer useful. Each regrind to sharpen a punch removes 1 mm of punch life. Because of the large number of strokes per tool regrind, this is considered to be a continuous distribution. The normal curve probability distribution is applicable. Given your analysis, what is the probability that the tool will be pulled for regrind 20 times?
