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Finding the Fourth Proportional to 784.66, 1,082.88 and 489.90

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Solution

The fourth proportional to 784.66, 1,082.88 and 489.90 is: 676.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.66 : 1,082.88 = 489.90 : x
  2. Step 2: Convert to fraction form
    784.66/1,082.88 = 489.90/x
  3. Step 3: Cross multiply
    784.66x = 1,082.88 × 489.90
  4. Step 4: Simplify right side
    784.66x = 530,502.91
  5. Step 5: Solve for x
    x = 530,502.91/784.66
  6. Step 6: Final answer
    x = 676.09

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.