Answer:
There is no error, Amad is correct.
Step-by-step explanation:
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Answer : Direct Variation
Question :
Identify the variation as direct, inverse, joint or combined. A = 
We know direct variation is y = kx
Where k is the constant of proportionality
When value of x increases then y also increases. when x value decreases then y value decreases.
The value of y depends on value of x It means y is directly proportional to x.
Hence A =
is a direct variation.
Answer:
Explanatory variable : web page design
Response variables : Visitor's rating and amount of time visiting the site.
Kindly check explanation for the rest.
Step-by-step explanation:
The explanatory variable simply means the independent or predictor variable which is used to bring about a change in the dependent or predicted variable. The explanatory variable in the scenario above is the web page design which is used to measure the behavior and changes in the response variable which are the rating given by visitors and the number of visits on each of the two different web page designs available (explanatory variable).
The confounding factor which may affect the study is the different area assigned to test the effectiveness of each page ; designating one page for the Oakland area and the other for Miami. User preferences for each area may itself mask the actual outcome of the experiment.
3/4=15
let,
total mass is x
x=4×15/3
=20 kg
so, total mass = 20 kg
=2×20/5
=2×4
=8 kg
Hope this helps!