Answer:
$19,500
Step-by-step explanation:
In this question, the first thing we do
Is to calculate the amount of gold that was used in making 7,800 smartphones. We proceed as follows:
Firstly, 10 ounces made 5,200 smartphones, then x ounces will make 7,800 smartphones
Thus 10 * 7,800 = 5,200 * x
x = 78,000/5200 = 15 ounces
This means that 7,800 smartphones were made using 15 ounces of gold
Now, we know that the value of an ounce is $1,300. Thus, the value of 15 ounces would be 15 * 1,300 = $19,500