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Finding the Fourth Proportional to 418.89, 578.43 and 288.21

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Solution

The fourth proportional to 418.89, 578.43 and 288.21 is: 397.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.89 : 578.43 = 288.21 : x
  2. Step 2: Convert to fraction form
    418.89/578.43 = 288.21/x
  3. Step 3: Cross multiply
    418.89x = 578.43 × 288.21
  4. Step 4: Simplify right side
    418.89x = 166,709.31
  5. Step 5: Solve for x
    x = 166,709.31/418.89
  6. Step 6: Final answer
    x = 397.98

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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.