Answer:
The area (probability) is: 0.6864.
Step-by-step explanation:
According to the statement, we are in front of a normal distribution with the following parameters:
µ (mean) = 0
σ (Standard deviation) = 1.
Then we need to find the area of the shaded region, which is the area between the points -1.21 < z < 0.84.
And the area (probability) is: 0.6864.