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Finding the Fourth Proportional to 420.15, 579.40 and 379.14

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Solution

The fourth proportional to 420.15, 579.40 and 379.14 is: 522.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.15 : 579.40 = 379.14 : x
  2. Step 2: Convert to fraction form
    420.15/579.40 = 379.14/x
  3. Step 3: Cross multiply
    420.15x = 579.40 × 379.14
  4. Step 4: Simplify right side
    420.15x = 219,673.72
  5. Step 5: Solve for x
    x = 219,673.72/420.15
  6. Step 6: Final answer
    x = 522.85

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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.