Because n > 30, the sampling distribution of the mean ages can be approximated by a normal distribution with mean µ and standard deviation σ ÷ √(45) .The central limit theory applies whenever n > 30. Because n > 30, the sampling distribution of the mean ages can be approximated by a normal distribution with mean µ and standard deviation σ ÷ √(n) .
ik im late but..
Option B would be the correct answer.. 5.5 basically
Answer:
170.
Step-by-step explanation:
The number of cell phones = 68 * 3/2
= 102.
Total = 102 + 68
= 170 phones.
If we multiply the bottom equation by 2 and move x to the right, it becomes:
4y = 2x-38
Now we can substitute it for the 4y in the top equation:
3x + (2x-38) = -23 => 5x = -23+38 => 5x = 15 => x=3
Then 4y = 2*3-38 => y = -8
So the solution is (3,-8)
