Answer:
This is an observational study based on a stratified sample.
Step-by-step explanation:
This study aimed to check which clean-up/drying up method after handwashing was more effective; that is, do dryers eliminate more germs than paper towels.
It involved 100 people that took part in the study. The 100 of them contaminated their hands and were instructed to wash their hands with soap and water for 15 seconds before the participants are randomly grouped into two strata; one stratum/group (consisting of 50 participants) that dries their hands with a dryer and another (also consisting of 50 participants) that dry their hands with paper towels.
An observational study is one in which data is collected only by monitoring the events of the study. The conductor of the study in no way tries to intervene or control any of the variables being studied. No control, no tweaking of factors, just observe and record data.
An observational study based on a stratified sample is an observational study that uses the stratified sampling method to carry out its objectives. It randomly puts each of the participants being observed into groups or strata. Each group of randomly assigned participants are then required to run the test for one of the variables being compared.
This is exactly what the study in the question describes. This is why this study is undoubtedly an observational study based on a stratified sample.
Hope this Helps!!!
Answer:
y³ - 3y² + 1/y+3
Step-by-step explanation:
y² - 9 = (y - 3) ( y + 3)
y-3/(y-3)(y+3) = 1/y+3
Answer:
-4;-4
Step-by-step explanation:
these would be the coords because each of the lines represents 2 units
The required simplified value of $10.40 to $13.12 is $2.72.
Given that,
To determine the simplified value of $10.40 to $13.12.
<h3>What is simplification?</h3>
The process in mathematics to operate and interpret the function to make the function or expression simple or more understandable is called simplifying and the process is called simplification.
Here,
In the question, asked about the difference between the numbers
$10.40 to $13.12
= 13.12 - 10.40
= $2.72
Thus, the required simplified value of $10.40 to $13.12 is $2.72.
Learn more about simplification here:
brainly.com/question/12501526
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The value of the given expression (3m - n)² + 4m when m = 63 and n = 45 is equal to 20,916.
<h3>What is an expression?</h3>
An expression can be defined as a mathematical equation which is used to show the relationship existing between two or more variables and numerical quantities.
<u>Given the following variables:</u>
Substituting the given variables into the given expression, we have;
Expression = (3m - n)² + 4m.
Expression = (3(63) - 45)² + 4(45).
Expression = (189 - 45)² + 180
Expression = 144² + 180
Expression = 20,736 + 180
Expression = 20,916.
Read more on expressions here: brainly.com/question/28260012
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Complete Question:
Evaluate the expression when m = 63 and n = 45. (3m - n)² + 4m.
