Answer:
1. 90% 2. 10% 3. 50%
Step-by-step explanation:
Given a mean score of 300 days and a standard deviation of 50 days, we want to find the cumulative probability that bulb life is less than or equal to 365 days. Thus, we know the following:
The value of the normal random variable is 365 days.
The mean is equal to 300 days.
The standard deviation is equal to 50 days.