Answer:
0.0548
Step-by-step explanation:
The distribution of life span for a certain type of battery is approximately normal with mean 2.5 hours and standard deviation 0.25 hour.
To find the the probability that a selected battery will have a life span of at most 2.1 hours, we need to first determine the z-score for x=2.1 hours using
We substitute the values to get:
We read read -1.6 from the standard normal distribution table to get:
P(X≤2.1)=0.0548