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Finding the Fourth Proportional to 388.80, 529.20 and 388.80

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Solution

The fourth proportional to 388.80, 529.20 and 388.80 is: 529.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.80 : 529.20 = 388.80 : x
  2. Step 2: Convert to fraction form
    388.80/529.20 = 388.80/x
  3. Step 3: Cross multiply
    388.80x = 529.20 × 388.80
  4. Step 4: Simplify right side
    388.80x = 205,752.96
  5. Step 5: Solve for x
    x = 205,752.96/388.80
  6. Step 6: Final answer
    x = 529.20

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.