Answer:
The minimum sample size required is 5,499 computer users.
The major obstacle is that it is a big sample size if it is a small organization wanting to perform it.
Step-by-step explanation:
We need to calculate a sample size in order to have 95% confidence interval with 12 minutes of witdth.
So, we have that the difference between the upper limit and the lower limit is 12:


For a 95% CI, the value of z is 1.96. The standard deviation is 227.

The minimum sample size required is 5,499 computer users.
Answer:
Range!
Step-by-step explanation:
It's the range because it's subtracting largest and smallest number in the set.
That's a 3x3 linear system. Let's do Gaussian elimination
4 3 1 -10 A
1 -3 2 -8 B
11 -2 3 -38 C
0 15 -7 22 D=A-4B
0 31 -19 50 E=C-11B
0 1 -7/15 22/15 F=D/15
1 0 3/5 -18/5 G=B+3F
0 0 -68/15 68/15 H=E-31F -19-31(-7/15), 50-31(22/15)
0 0 1 -1 I=-15/68 H
1 0 0 -3 J=G - 3/5 I
0 1 0 1 K=F+ 7/15 I
We read off from the last three lines the
Answer: x=-3, y=1, z=-1