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Finding the Fourth Proportional to 1,206.20, 1,806.90 and 657.40

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Solution

The fourth proportional to 1,206.20, 1,806.90 and 657.40 is: 984.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,206.20 : 1,806.90 = 657.40 : x
  2. Step 2: Convert to fraction form
    1,206.20/1,806.90 = 657.40/x
  3. Step 3: Cross multiply
    1,206.20x = 1,806.90 × 657.40
  4. Step 4: Simplify right side
    1,206.20x = 1,187,856.06
  5. Step 5: Solve for x
    x = 1,187,856.06/1,206.20
  6. Step 6: Final answer
    x = 984.79

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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.