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Finding the Fourth Proportional to 629.82, 869.40 and 420.18

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Solution

The fourth proportional to 629.82, 869.40 and 420.18 is: 580.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.82 : 869.40 = 420.18 : x
  2. Step 2: Convert to fraction form
    629.82/869.40 = 420.18/x
  3. Step 3: Cross multiply
    629.82x = 869.40 × 420.18
  4. Step 4: Simplify right side
    629.82x = 365,304.49
  5. Step 5: Solve for x
    x = 365,304.49/629.82
  6. Step 6: Final answer
    x = 580.01

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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.