The key on a pictograph tells what each picture stands for.
Answer:
c. observational study
Step-by-step explanation:
<em>Researchers compare the rates of autism for children who did and did not receive the standard measles-mumps-rubella vaccine, to see if the vaccine might be responsible for autism in some children.</em>
This study design in the above scenario is observational study because the researcher are obviously observing whether the vaccine is affecting the children. Note that Observational study is like experiment which attempts to understand the cause and effect relationships on a subject.
You need to post an actual question on her to be answered
Let's solve this problem step-by-step.
STEP-BY-STEP SOLUTION:
We will be using simultaneous equations to solve this problem.
First we will establish the equations which we will be using as displayed below:
Equation No. 1 -
A + B = 90°
Equation No. 1 -
A = 2B + 12
To begin with, let's make ( A ) the subject in the first equation as displayed below:
Equation No. 1 -
A + B = 90
A = 90 - B
Next we will substitute the value of ( A ) from the first equation into the second equation and solve for ( B ) as displayed below:
Equation No. 2 -
A = 2B + 12
( 90 - B ) = 2B + 12
- B - 2B = 12 - 90
- 3B = - 78
B = - 78 / - 3
B = 26°
Then we will substitute the value of ( B ) from the second equation into the first equation to solve for ( A ) as displayed below:
A = 90 - B
A = 90 - ( 26 )
A = 64°
ANSWER:
Therefore, the answer is:
A = 64°
B = 26°
Please mark as brainliest if you found this helpful! :)
Thank you <3