You mean their sum is 12?
A) x + y = 12
B) x -y = 4 then we add both equations:
2x = 16
x = 8
y = 4
Answer: I think 5.3
Step-by-step explanation:
I did the a method then checked over it :/
Answer:
I can't show you BC I need paper to show u sorry
500 is one tenth as much as 50 is correct.
500 of 1/10=50
<span>500 is 10 times as much as 50 is wrong.
</span>500 x 10= 5,000 not 50
Answer:
Step-by-step explanation:
<u>Standard Deviation and Variance</u>
If we have a data set of measured values the variance is defined as the average of the squared differences that each value has from the mean. The formula to calculate the variance is:
Where 
is the mean of the measured values xi (i running from 1 to n), and n is the total number of values.
The standard deviation is known by the symbol 
and is the square root of the variance. We know the standar deviation of the weight in kg of a group of teenagers to be 8.6 kg. Thus, the variance is
