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Finding the Fourth Proportional to 420.30, 629.24 and 379.80

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Solution

The fourth proportional to 420.30, 629.24 and 379.80 is: 568.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.30 : 629.24 = 379.80 : x
  2. Step 2: Convert to fraction form
    420.30/629.24 = 379.80/x
  3. Step 3: Cross multiply
    420.30x = 629.24 × 379.80
  4. Step 4: Simplify right side
    420.30x = 238,983.45
  5. Step 5: Solve for x
    x = 238,983.45/420.30
  6. Step 6: Final answer
    x = 568.60

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.