Answer :
The proportion of people spending 4 hours or less on their computer per day is approximately 21.19%. Out of 100,000 people, approximately 21,190 are expected to spend 4 hours or less on their computers.
Part 1: Proportion of people spending 4 hours or less
To solve this, we need to convert the time (4 hours) into a z-score.
z = (X - μ) / σ
z = (4 - 5) / 1.25 = -0.8
Using a z-table, we find that the area to the left of z = -0.8 is approximately 0.2119.
So, 21.19% of people spend 4 hours or less on their computers.
Part 2: Number of people spending 4 hours or less out of 100,000
If 21.19% of people spend 4 hours or less, then out of 100,000 people, the number of people spending 4 hours or less is:
0.2119 * 100,000 = 21,190 people.
Approximately 21,190 people out of 100,000 are expected to spend 4 hours or less on their computers.