400 should be the answer. Hope this helps!
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:
5 kmph
Step-by-step explanation:
Given: Greg swam 4 kilometers against the current.
Greg swam 16 kilometers with the current.
Rate of the current was 3kmph.
Lets assume the speed of greg swimming with no current be "x".
∴ Speed of swimming against current= 
Speed of swimming with current= 
As given, it took same amount of time to swim both with current and against current.
∴ Forming an equation to find the value of x, which is speed of greg swimming with no current.
We know, 
⇒ 
Multiplying both side by (x+3) and (x-3)
⇒
Using distributive property of multiplication.
⇒ 
Subtracting both side by 4x and adding by 48.
⇒
Dividing both side by 12
⇒
Hence, Greg can swim at the rate of 5kmph with no current.
Answer:
Option (3)
Step-by-step explanation:
Properties for the vertical stretch or shrink of a function,
If a function is f(x) = k|x|
1). Function will be vertically stretched if k > 1
2). Function will have a vertical shrink if 0 < k < 1
To fit the given data graph of f(x) = |x| will vertically shrink without any translation along x or y-axis.
And the value of k will be, 0 < k < 1.
Therefore, g(x) = 
will be the transformed graph.
Therefore, Option (3) will be the correct option.
Answer:
2011
Step-by-step explanation:
because it lapped it by a couple of years equaling 2
