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Finding the Fourth Proportional to 856.89, 1,285.32 and 279.75

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Solution

The fourth proportional to 856.89, 1,285.32 and 279.75 is: 419.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.89 : 1,285.32 = 279.75 : x
  2. Step 2: Convert to fraction form
    856.89/1,285.32 = 279.75/x
  3. Step 3: Cross multiply
    856.89x = 1,285.32 × 279.75
  4. Step 4: Simplify right side
    856.89x = 359,568.27
  5. Step 5: Solve for x
    x = 359,568.27/856.89
  6. Step 6: Final answer
    x = 419.62

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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.