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Finding the Fourth Proportional to 420.61, 628.07 and 343.72

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Solution

The fourth proportional to 420.61, 628.07 and 343.72 is: 513.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.61 : 628.07 = 343.72 : x
  2. Step 2: Convert to fraction form
    420.61/628.07 = 343.72/x
  3. Step 3: Cross multiply
    420.61x = 628.07 × 343.72
  4. Step 4: Simplify right side
    420.61x = 215,880.22
  5. Step 5: Solve for x
    x = 215,880.22/420.61
  6. Step 6: Final answer
    x = 513.26

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.