Posted by Laura on .
You invent a new system to make excellent racing tires for the Indianapolis 500/ Your tires are good for an average of 105 miles, with a standard deviation of 7.5 miles. What is the probability that one of your tires can go for at least 44 laps? What is the probability that one of your tires will fail before the end of 36 laps?

Math  Probability 
Reiny,
How far is a lap?

Math  Probability 
Lindsey,
One lap is 2.5 miles.
Sorry, meant to include that before. 
Math  Probability 
Reiny,
so 44 laps = 44(2.5) or 110 miles
36 laps = 90 miles
enter your values in
http://davidmlane.com/hyperstat/z_table.html
enter 110 for 44 laps in "above" > .2525
enter 90 and click on "below" > .02275