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Finding the Fourth Proportional to 2,808, 4,212.64 and 860

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Solution

The fourth proportional to 2,808, 4,212.64 and 860 is: 1,290.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,808 : 4,212.64 = 860 : x
  2. Step 2: Convert to fraction form
    2,808/4,212.64 = 860/x
  3. Step 3: Cross multiply
    2,808x = 4,212.64 × 860
  4. Step 4: Simplify right side
    2,808x = 3,622,870.40
  5. Step 5: Solve for x
    x = 3,622,870.40/2,808
  6. Step 6: Final answer
    x = 1,290.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.