Answer:

Using the frequency distribution, I found the mean height to be 70.2903 with a standard deviation of 3.5795
Step-by-step explanation:
Given
See attachment for class
Solving (a): Fill the midpoint of each class.
Midpoint (M) is calculated as:

Where
Lower class interval
Upper class interval
So, we have:
Class 63-65:

Class 66 - 68:

When the computation is completed, the frequency distribution will be:

Solving (b): Mean and standard deviation using 1-VarStats
Using 1-VarStats, the solution is:


<em>See attachment for result of 1-VarStats</em>
Answer: Justin is shown in 15 pictures with friends, 6 with family, and 8 with only him
Step-by-step explanation: Hope this helps :)
Is this simultaneous equations?
if yes then the first step is
make one of the unknown as the subject
Answer:
C
Step-by-step explanation:
|2x - 2| < 8
it implies that
2x - 2 < 8
2x -2 + 2 < 8 + 2
2x < 10
x < 5
or
-(2x - 2) < 8
-2x + 2 < 8
-2x + 2 - 2 < 8 - 2
- 2x < 6
x > -3 ( the sense of the inequality reverse because I divided by minus)
The solution can be combine to
-3<x<5