Answer:
The correct answer is:
1. Every ratio yx for related pairs of x and y is equivalent.
Step-by-step explanation:
Proportion is defined as the relationship between two quantities. When one quantity changes the other is also changes.
For two quantities y and x when we say that both are proportional then t can be written as:
y∝x
Removing the proportionality symbol introduces a constant which is the ratio of y and x.

This ratio of y and x, i.e. k is equivalent for all related pairs of x and y.
Hence,
The correct answer is:
1. Every ratio yx for related pairs of x and y is equivalent.
The answer is -14 degrees centigrade
Answer: We can find out the missing statement with help of below explanation.
Step-by-step explanation:
We have a rectangle ABCD with diagonals AC and BD ( shown in given figure.)
We have to prove: Diagonals AC and BD bisect each other.
In triangles, AED and BEC.
( By alternative angle theorem)
( Because ABCD is a rectangle)
( By alternative angle theorem)
By ASA postulate,
By CPCTC,
and 
⇒ BE= ED and CE=EA
By the definition of bisector, AC and BD bisect each other.