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Finding the Fourth Proportional to 669.12, 923.42 and 420.35

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Solution

The fourth proportional to 669.12, 923.42 and 420.35 is: 580.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.12 : 923.42 = 420.35 : x
  2. Step 2: Convert to fraction form
    669.12/923.42 = 420.35/x
  3. Step 3: Cross multiply
    669.12x = 923.42 × 420.35
  4. Step 4: Simplify right side
    669.12x = 388,153.67
  5. Step 5: Solve for x
    x = 388,153.67/669.12
  6. Step 6: Final answer
    x = 580.10

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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.