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Finding the Fourth Proportional to 418.32, 628.38 and 393.66

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Solution

The fourth proportional to 418.32, 628.38 and 393.66 is: 591.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.32 : 628.38 = 393.66 : x
  2. Step 2: Convert to fraction form
    418.32/628.38 = 393.66/x
  3. Step 3: Cross multiply
    418.32x = 628.38 × 393.66
  4. Step 4: Simplify right side
    418.32x = 247,368.07
  5. Step 5: Solve for x
    x = 247,368.07/418.32
  6. Step 6: Final answer
    x = 591.34

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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.