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.
Answer:
{- 11, - 1 }
Step-by-step explanation:
Since the coefficient of the x² term is 1 , to complete the square
add (half the coefficient of the x-term )² to both sides
x² + 2(6)x + 36 = - 11 + 36 ← complete the square on the left side
(x + 6)² = 25 ( take the square root of both sides
= ± 
x + 6 = ± 5 ( subtract 6 from both sides )
x = - 6 ± 5
x = - 6 + 5 = - 1 or x = - 6 - 5 = - 11
Answer: 990.9 .9+ 990
Step-by-step explanation: you have to do order of operations witch is PEMDAS so you do Parentheses then exponents multiplication or division and addition or subtraction but you do it depending how it starts and in this case you have to subtract the 2 numbers and then add the answer of the multiplication problem
