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Finding the Fourth Proportional to 784.04, 1,081.44 and 489.20

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Solution

The fourth proportional to 784.04, 1,081.44 and 489.20 is: 674.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    784.04 : 1,081.44 = 489.20 : x
  2. Step 2: Convert to fraction form
    784.04/1,081.44 = 489.20/x
  3. Step 3: Cross multiply
    784.04x = 1,081.44 × 489.20
  4. Step 4: Simplify right side
    784.04x = 529,040.45
  5. Step 5: Solve for x
    x = 529,040.45/784.04
  6. Step 6: Final answer
    x = 674.76

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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.