Class interval (minutes) # dryer failed (frequency)

1000 - 1100 47

1100 - 1200 38

1200 - 1300 84

1300 - 1400 66

1400 - 1500 107

1500 - 1600 47

1600 - 1700 16

1700 - 1800 29

1800 - 1900 4

Randomly selected hair dryers of a particular brand have been used continuously and their life-times noted in above given schedule.

Find the survival probability or reliability at time = 1200 Hrs

Round answer to TWO decimal places.