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Finding the Fourth Proportional to 420.66, 628.16 and 343.77

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Solution

The fourth proportional to 420.66, 628.16 and 343.77 is: 513.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.66 : 628.16 = 343.77 : x
  2. Step 2: Convert to fraction form
    420.66/628.16 = 343.77/x
  3. Step 3: Cross multiply
    420.66x = 628.16 × 343.77
  4. Step 4: Simplify right side
    420.66x = 215,940.84
  5. Step 5: Solve for x
    x = 215,940.84/420.66
  6. Step 6: Final answer
    x = 513.34

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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.