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Finding the Fourth Proportional to 420.19, 579.89 and 245.57

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Solution

The fourth proportional to 420.19, 579.89 and 245.57 is: 338.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.19 : 579.89 = 245.57 : x
  2. Step 2: Convert to fraction form
    420.19/579.89 = 245.57/x
  3. Step 3: Cross multiply
    420.19x = 579.89 × 245.57
  4. Step 4: Simplify right side
    420.19x = 142,401.30
  5. Step 5: Solve for x
    x = 142,401.30/420.19
  6. Step 6: Final answer
    x = 338.90

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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.