A) The constant of proportionality in this proportional relationship is 
B) The equation to represent this proportional relationship is y = 0.2x
<h3><u>Solution:</u></h3>
Given that,
The amount Naomi pays each month for international text messages is proportional to the number of international texts she sends that month
Therefore,
This is a direct variation proportion

Let "y" be the amount that Naomi pays each month
Let "x" be the number of international texts she sends that month
Therefore,

y = kx -------- eqn 1
Where, "k" is the constant of proportionality
Thus the constant of proportionality in this proportional relationship is:

<em><u>Last month, she paid $3.20 for 16 international texts</u></em>
Therefore,
y = 3.20
x = 16
Thus from eqn 1,

Substitute k = 0.2 in eqn 1
y = 0.2x
The equation would then be y = 0.2x
The increasing and decreasing intervals are marked on the graph and attached below.
The red arrow mark shows the part where graph is decreasing
The green arrow mark shows the part where graph is increasing
There is no end point or starting point for the graph
The graph starts decreasing at -∞ and it decreases till it reaches -2.5
Also the graph start decreasing at 0 and goes to +∞
So we have two decreasing intervals
(-∞ , -2.5) U (0, ∞)
The graph starts increasing at -2.5 and it increases till it reaches 0
So increasing interval is
(-2.5, 0)
An equinox is when there are equal amounts of daylight and hours in the night. The equinox falls twice in a year and there is a winter solstice and a summer solstice.
<h3>
Answer: Choice C) $1125</h3>
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Explanation:
We'll add up the values in the bottom row of the table.
A value like +150 is the same as simply saying 150
The negatives stick around.
Adding up the values in that row gets us
150 + (-50) + 400 + 300 + (-175) + (-250) = 375
This indicates that over the entire 6 month period, the overall change is +375
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In other words, the initial investment (call it x) has increased by 375 dollars over the 6 month period.
We can then say:
x + 375 = 1500
x = 1500-375
x = 1125
She initially invested $1125