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Finding the Fourth Proportional to 803.20, 1,204.80 and 438.70

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Solution

The fourth proportional to 803.20, 1,204.80 and 438.70 is: 658.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    803.20 : 1,204.80 = 438.70 : x
  2. Step 2: Convert to fraction form
    803.20/1,204.80 = 438.70/x
  3. Step 3: Cross multiply
    803.20x = 1,204.80 × 438.70
  4. Step 4: Simplify right side
    803.20x = 528,545.76
  5. Step 5: Solve for x
    x = 528,545.76/803.20
  6. Step 6: Final answer
    x = 658.05

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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.