All you need to do is pull out the common factor of
:
Answer:
The sum of 78 and -78 is zero.
Step-by-step explanation:
I used a calculator ;)
This is an example of "a stratified sample".
<u>Answer:</u> Option B
<u>Explanation:</u>
A group-based sampling process that can be divided into subpopulations. For statistical studies, testing of each subpopulation separately may be useful if subpopulations within a total population differ, thus understood as "Stratified sampling".
One might, for instance, divide a adults sample into subgroups in terms of age, like 18 to 29, 30 to 39, 40 to 49, 50–59 etc with decided age difference as needed. A stratified sample may be more accurate than an easy sample of the similar size by random. As it offers more accuracy, a stratified sample sometimes involves a smaller sample, saving money.
Answer:
18
Step-by-step explanation:
36/4=9 9/2=4.5 4.5+4.5+4.5+4.5=18
