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Finding the Fourth Proportional to 784.43, 1,083.20 and 490.20

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Solution

The fourth proportional to 784.43, 1,083.20 and 490.20 is: 676.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.43 : 1,083.20 = 490.20 : x
  2. Step 2: Convert to fraction form
    784.43/1,083.20 = 490.20/x
  3. Step 3: Cross multiply
    784.43x = 1,083.20 × 490.20
  4. Step 4: Simplify right side
    784.43x = 530,976.77
  5. Step 5: Solve for x
    x = 530,976.77/784.43
  6. Step 6: Final answer
    x = 676.90

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1.5x scale

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.