Using the weighed mean formula, it is found that Mara's average for the course was of 68.6.
<h3>What is the weighed mean?</h3>
The weighed mean is given by the <u>sum of all elements in a data-set multiplied by it's weight, divided by the sum of the weights</u>.
In this problem, the weights are as follows:
- A quiz has a weight of 1.
- A test has a weight of 2.
- The final examination has a weight of 4.
Hence, her weighed mean is given as follows:

Mara's average for the course was of 68.6.
More can be learned about the weighed mean formula at brainly.com/question/24398353
 
        
             
        
        
        
4x + 6 - 3 = 8
4x + 3 = 8
4x = 8 - 3
4x = 5
x = 5/4 <==
        
                    
             
        
        
        
The  answer is 5  and  2/5. Hopefully it is correct!
        
             
        
        
        
Answer:
Stefanie bought 10 erasers
Step-by-step explanation:
We can establish the following equation:
TP = NP*PP + NE*EP
Where:
TP = Total price; (4.25)
NP = Number of pencil packages; (1)
PP = Pencil Package's Price; (1.75)
NE = Number of erasers; (What we are looking for)
EP = Erasers Price; (0.25);
Then:
4.25 = 1*1.75 + NE*0.25;
4.25 - 1.75 = NE*0.25;
2.5/0.25 = NE;
10 = NE.
 
        
             
        
        
        
Answer:
   70 -20x = 60 -15x
Step-by-step explanation:
The amount of money left on Josh's card is ...
   70 -20x
The amount of money left on Jessica's card is ...
   60 -15x
These amounts are the same when ...
   70 -20x = 60 -15x
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<em>Additional comment</em>
The solution to this equation is ...
   10 = 5x   ⇒   x = 2 . . same amount after purchase of 2 pizzas