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Finding the Fourth Proportional to 420.63, 629.79 and 396.35

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Solution

The fourth proportional to 420.63, 629.79 and 396.35 is: 593.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.63 : 629.79 = 396.35 : x
  2. Step 2: Convert to fraction form
    420.63/629.79 = 396.35/x
  3. Step 3: Cross multiply
    420.63x = 629.79 × 396.35
  4. Step 4: Simplify right side
    420.63x = 249,617.27
  5. Step 5: Solve for x
    x = 249,617.27/420.63
  6. Step 6: Final answer
    x = 593.44

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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.