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Finding the Fourth Proportional to 856.86, 1,285.65 and 424.02

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Solution

The fourth proportional to 856.86, 1,285.65 and 424.02 is: 636.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.86 : 1,285.65 = 424.02 : x
  2. Step 2: Convert to fraction form
    856.86/1,285.65 = 424.02/x
  3. Step 3: Cross multiply
    856.86x = 1,285.65 × 424.02
  4. Step 4: Simplify right side
    856.86x = 545,141.31
  5. Step 5: Solve for x
    x = 545,141.31/856.86
  6. Step 6: Final answer
    x = 636.21

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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.