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Finding the Fourth Proportional to 668.87, 922.89 and 420.10

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Solution

The fourth proportional to 668.87, 922.89 and 420.10 is: 579.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.87 : 922.89 = 420.10 : x
  2. Step 2: Convert to fraction form
    668.87/922.89 = 420.10/x
  3. Step 3: Cross multiply
    668.87x = 922.89 × 420.10
  4. Step 4: Simplify right side
    668.87x = 387,705.72
  5. Step 5: Solve for x
    x = 387,705.72/668.87
  6. Step 6: Final answer
    x = 579.64

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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.