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Finding the Fourth Proportional to 475.18, 711.72 and 420.49

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Solution

The fourth proportional to 475.18, 711.72 and 420.49 is: 629.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    475.18 : 711.72 = 420.49 : x
  2. Step 2: Convert to fraction form
    475.18/711.72 = 420.49/x
  3. Step 3: Cross multiply
    475.18x = 711.72 × 420.49
  4. Step 4: Simplify right side
    475.18x = 299,271.14
  5. Step 5: Solve for x
    x = 299,271.14/475.18
  6. Step 6: Final answer
    x = 629.81

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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.