Answer:
0.3114
Option d is right
Step-by-step explanation:
Let X be the time spent on a treadmill in the health club
Given that research shows that on average, patrons spend an average of 42.5 minutes on the treadmill, with a standard deviation of 5.4 minutes
Also given that X is normal
the probability that randomly selected individual would spent between 30 and 40 minutes on the treadmill.
round off to two decimals tog et
the probability that randomly selected individual would spent between 30 and 40 minutes on the treadmill is 0.31
Hence option d is right