Answer:
(9 ^ 3) x 0.04 (4/99)
Step-by-step explanation:
This seems overwhelming, but after simplifying, it will look much easier
Numerator (First Row)
First, we will combine like terms and simplify the top row
(9 ^ <em>x</em> + 1) x 8 - (9 ^ <em>x</em> - 1) x 81
(9 ^ <em>x</em> + 1) - (9 ^ <em>x</em> - 1) x (8 x 81)
(9 ^ 2x) x 648
Denominator (Second Row)
Next, we can combine like terms and simplify the second row
(9 ^ <em>x</em>) x 66 - (9 ^ <em>x</em> - 2) x 243
(9 ^ <em>x</em>) - (9 ^ <em>x</em> - 2) x (66 x 243)
(9 ^ 2x + 2) x 16,038
Simplify
Our expression is now
(9 ^ 2x) x 648
(9 ^ 2x + 2) x 16,038
We can simplify it as
(9 ^ 3) x 0.04 (4/99)
Answer is in the attachment below.
The confounding variable which is controlled by randomly assigning individuals to treatments is: C. the time of day participants drank the beverages.
<h3>What is a
confounding variable?</h3>
A confounding variable is also referred to as a confounder and it can be defined as a type of variable that has the ability to influence both the independent and dependent variables.
Also, a confounding variable is usually not accounted for by the researcher and as such it can cause a spurious association between the independent and dependent variables.
In this context, we can infer and logically deduce that the time of day at which participants drank the beverages is a confounding variable which is controlled by randomly assigning individuals to treatments.
Read more on confounding variable here: brainly.com/question/10863424
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