c. 4.6
21 X .22= 4.6
Calculating the variance requires finding the product of 21 and 22%. To make this easier we convert 22% into it's decimal form and construct the equation. To back check this answer we can use 10% of 21 voters which equals 2.1% then double that amount to reach 4.2%, knowing that we now have a close approximation of the variance we can eliminate answers a, b, and d, leaving c as the only logical choice.
You wanna find a common denominator so put the problem like this
3 1/3.< You wanna take 3 (denominator)
And times it
By 5 then you wanna take the 5. - 2 2/5.< (deniminator) and times it by 3.
____ Your common denominator is 15
now it will look like this
3 1/15
-2 2/15
———-
Now subtract. You will need to borrow 1 from 3 since you cant subtract 2 by 1 so the 3 will become a 2 and the 1 will be come 11 and here you can subtract so this will be your answer.
2 11/15
-2 2/15
-———-
0 9/15
Thats your official answer 9/15 hope I helped :)
Road learning: Just take out one 0 for tens, two 0 for hundreds and three 0 for thousands. The answer is 600.
Oder of operations is this;
First thing you have to do is take the 5 + -8 which equals -3 then you have to 33-18 which equals 15 then u have to divide by the -3 which gives you equal your answer of -5