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Finding the Fourth Proportional to 660.77, 990.26 and 429.54

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Solution

The fourth proportional to 660.77, 990.26 and 429.54 is: 643.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.77 : 990.26 = 429.54 : x
  2. Step 2: Convert to fraction form
    660.77/990.26 = 429.54/x
  3. Step 3: Cross multiply
    660.77x = 990.26 × 429.54
  4. Step 4: Simplify right side
    660.77x = 425,356.28
  5. Step 5: Solve for x
    x = 425,356.28/660.77
  6. Step 6: Final answer
    x = 643.73

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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.