Luna entered a raffle for a new pair of running shoes. She purchased 20 tickets and was told that she had a 20% chance of winnin
g. How many tickets were sold? P (Luna winning) = StartFraction Number of tickets purchased over Total number of tickets sold EndFraction. 20 percent = StartFraction 20 over x EndFraction. One-fifth = StartFraction 20 over x EndFraction. x = tickets
A normal curve has approximately 95% of graph between mean - 2sd and mean + 2sd So 95% of the times will be between 0 and 12 minutes. 6 - 2x3 to 6 + 2x3 2.5% will take over 12 minutes
Strangely 2.5% will also take less than 0 minutes to process which shows the normal curve is not perfect in this example.
