Assume you tested svereral Firestone tires and recorded their failure times (as defined by an engineer).After doing a Chi-Square test ,you decided taht failures are normally distributed ,with mean failure of 50,000 miles and a standard deviation of 10,000 miles .Determine the following:
a) reliability of the tires at 40,000 miles
b) given that a tire has been driven (on a test machine) 20,000 miles, determine its reliability at 60,000 miles.
Mean=M = 50,000 miles
Standard deviation =s= 10,000 miles
x= 40,000 miles
z=(x-M )/s= -1 =(40000-50000)/10000
Cumulative Probability corresponding to z= -1 is= 0.1587
Or Probability corresponding to x< 40,000 is ...
Reliability has been calculated using normal distribution.