Answer:
Constant of proportionality: 
Equation: 
Step-by-step explanation:
By definition, Direct proportion equations have the following form:

Where "k" is the Constant of proportionality.
In this case, let be "c" the the amount of caffeine consumed (in mg) from a glass of Diet Pepsi and "d" the number of ounces that was drank.
So, the equation that represents this relationship will have this form:

Then, the first step is to find the Constant of proportionality "k".
Knowing that:

We can substitute values into the equation:

Now, solving for "k", we get:

Therefore, we can write the following equation that represents that proportional relationship:

All estimating problems make the assumption you are familar with your math facts, addition and multiplication. Since students normally memorize multiplication facts for single-digit numbers, any problem that can be simplified to single-digit numbers is easily worked.
2. You are asked to estimate 47.99 times 0.6. The problem statement suggests you do this by multiplying 50 times 0.6. That product is the same as 5 × 6, which is a math fact you have memorized. You know this because
.. 50 × 0.6 = (5 × 10) × (6 × 1/10)
.. = (5 × 6) × (10 ×1/10) . . . . . . . . . . . by the associative property of multiplication
.. = 30 × 1
.. = 30
3. You have not provided any clue as to the procedure reviewed in the lesson. Using a calculator,
.. 47.99 × 0.6 = 28.79 . . . . . . rounded to cents
4. You have to decide if knowing the price is near $30 is sufficient information, or whether you need to know it is precisely $28.79. In my opinion, knowing it is near $30 is good enough, unless I'm having to count pennies for any of several possible reasons.
D = rt
/r /r
D/r = T
*sample text*
Answer:
C. $97
Step-by-step explanation:
The average of his wage for all 15 days is the sum of all wages for the 15 days divided by 15.
average wage for 15 days = (sum of wages for the 15 days)/15
The amount of wages during a number of days is the product of the average wage of those days and the number of days.
First 7 days:
average wage: $87
number of days: 7
total wages in first 7 days = 7 * $87/day = $609
Last 7 days:
average wage: $92
number of days: 7
total wages in last 7 days = 7 * $92/day = $644
8th day:
wages of the 8th day is unknown, so we let x = wages of the 8th day
total wages of 15 days = (wages of first 7 days) + (wages of 8th day) + (wages of last 7 days)
total wages of 15 days = 609 + x + 644 = x + 1253
average wage for 15 days = (sum of wages for the 15 days)/15
average wage for 15 days = (x + 1253)/15
We are told the average for the 15 days is $90/day.
(x + 1253)/15 = 90
Multiply both sides by 15.
x + 1253 = 1350
Subtract 1253 from both sides.
x = 97
Answer: $97