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Finding the Fourth Proportional to 669.06, 923.20 and 420.21

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Solution

The fourth proportional to 669.06, 923.20 and 420.21 is: 579.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.06 : 923.20 = 420.21 : x
  2. Step 2: Convert to fraction form
    669.06/923.20 = 420.21/x
  3. Step 3: Cross multiply
    669.06x = 923.20 × 420.21
  4. Step 4: Simplify right side
    669.06x = 387,933.52
  5. Step 5: Solve for x
    x = 387,933.52/669.06
  6. Step 6: Final answer
    x = 579.82

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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.