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Finding the Fourth Proportional to 856.76, 1,285.07 and 279.63

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Solution

The fourth proportional to 856.76, 1,285.07 and 279.63 is: 419.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.76 : 1,285.07 = 279.63 : x
  2. Step 2: Convert to fraction form
    856.76/1,285.07 = 279.63/x
  3. Step 3: Cross multiply
    856.76x = 1,285.07 × 279.63
  4. Step 4: Simplify right side
    856.76x = 359,342.73
  5. Step 5: Solve for x
    x = 359,342.73/856.76
  6. Step 6: Final answer
    x = 419.42

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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.