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Finding the Fourth Proportional to 856.90, 1,284.34 and 329.39

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Solution

The fourth proportional to 856.90, 1,284.34 and 329.39 is: 493.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.90 : 1,284.34 = 329.39 : x
  2. Step 2: Convert to fraction form
    856.90/1,284.34 = 329.39/x
  3. Step 3: Cross multiply
    856.90x = 1,284.34 × 329.39
  4. Step 4: Simplify right side
    856.90x = 423,048.75
  5. Step 5: Solve for x
    x = 423,048.75/856.90
  6. Step 6: Final answer
    x = 493.70

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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.