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Finding the Fourth Proportional to 856.83, 1,285.35 and 279.75

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Solution

The fourth proportional to 856.83, 1,285.35 and 279.75 is: 419.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.83 : 1,285.35 = 279.75 : x
  2. Step 2: Convert to fraction form
    856.83/1,285.35 = 279.75/x
  3. Step 3: Cross multiply
    856.83x = 1,285.35 × 279.75
  4. Step 4: Simplify right side
    856.83x = 359,576.66
  5. Step 5: Solve for x
    x = 359,576.66/856.83
  6. Step 6: Final answer
    x = 419.66

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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.