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Finding the Fourth Proportional to 438.72, 605.13 and 420.04

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Solution

The fourth proportional to 438.72, 605.13 and 420.04 is: 579.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.72 : 605.13 = 420.04 : x
  2. Step 2: Convert to fraction form
    438.72/605.13 = 420.04/x
  3. Step 3: Cross multiply
    438.72x = 605.13 × 420.04
  4. Step 4: Simplify right side
    438.72x = 254,178.81
  5. Step 5: Solve for x
    x = 254,178.81/438.72
  6. Step 6: Final answer
    x = 579.36

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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.