Answer:
1) 78.87%
2) 99.7%
Step-by-step explanation:
The z-score for a normal distribution is given by:
1- The given data is:
σ = 4 years
μ = 50 years
For X = 45 and X =55
A z-score of -1.25 corresponds to the 10.57th percentile of a normal distribution, while a z-score of 1.25 is equivalent to the 89.44th percentile.
Therefore, the percentage of the alligators are between 45 and 55 years old is:
78.87% of alligators.
2- The given data is:
σ = 2 minutes
μ = 17 minutes
For X = 11 and X =23
A z-score of -3.0 corresponds to the 0.135th percentile of a normal distribution, while a z-score of 3.0 is equivalent to the 99.865th percentile.
Therefore, the percentage of people that should be seen by the doctor between 11 and 23 minutes is:
99.7% of people.