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Finding the Fourth Proportional to 420.84, 579.60 and 388.44

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Solution

The fourth proportional to 420.84, 579.60 and 388.44 is: 534.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.84 : 579.60 = 388.44 : x
  2. Step 2: Convert to fraction form
    420.84/579.60 = 388.44/x
  3. Step 3: Cross multiply
    420.84x = 579.60 × 388.44
  4. Step 4: Simplify right side
    420.84x = 225,139.82
  5. Step 5: Solve for x
    x = 225,139.82/420.84
  6. Step 6: Final answer
    x = 534.98

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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.