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Finding the Fourth Proportional to 856.87, 1,284.28 and 394.25

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Solution

The fourth proportional to 856.87, 1,284.28 and 394.25 is: 590.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.87 : 1,284.28 = 394.25 : x
  2. Step 2: Convert to fraction form
    856.87/1,284.28 = 394.25/x
  3. Step 3: Cross multiply
    856.87x = 1,284.28 × 394.25
  4. Step 4: Simplify right side
    856.87x = 506,327.39
  5. Step 5: Solve for x
    x = 506,327.39/856.87
  6. Step 6: Final answer
    x = 590.90

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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.