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Finding the Fourth Proportional to 856.47, 1,279.50 and 545.85

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Solution

The fourth proportional to 856.47, 1,279.50 and 545.85 is: 815.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.47 : 1,279.50 = 545.85 : x
  2. Step 2: Convert to fraction form
    856.47/1,279.50 = 545.85/x
  3. Step 3: Cross multiply
    856.47x = 1,279.50 × 545.85
  4. Step 4: Simplify right side
    856.47x = 698,415.08
  5. Step 5: Solve for x
    x = 698,415.08/856.47
  6. Step 6: Final answer
    x = 815.46

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.