Answer: The standard deviation was calculated incorrectly.
Step-by-step explanation:
- The standard deviation measures the dispersion of the data values from the mean value.
It cannot be negative , because it is the square root of the variance .
We add all squared deviations from the data points away from the mean and (then divide it by the number of data values) to evaluate variance.
Since , any squared number cannot give a negative result.
⇒ Standard deviation cannot be negative.
⇒The standard deviation was calculated incorrectly.
Rest other things (given in options) can not be interpreted on the basis of given information.
Answer:
20
Step-by-step explanation:
So increased weight = 92-80 = 12
so ℅ = 12×100/80 = 15
so his weight is increased by 15℅ !!
Answer: 
Step-by-step explanation:
For this exercise it is important to remember the following:

Given the following expression:

You can notice that the radicand (the number inside the square root) is negative. Therefore, in order to simplify the expression, you need to follow these steps:
1. Replace
with
and simplify:

2. Descompose 12 into its prime factors:

3. Substitute into the expression:

4. Since
, you can simplify it:

There are 2 ways to turn a number into a percent...
(1) move the decimal 2 spaces to the right....0.3 = 30%
(2) multiply by 100....0.3 x 100 = 30%