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Finding the Fourth Proportional to 660.37, 990.89 and 429.71

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Solution

The fourth proportional to 660.37, 990.89 and 429.71 is: 644.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.37 : 990.89 = 429.71 : x
  2. Step 2: Convert to fraction form
    660.37/990.89 = 429.71/x
  3. Step 3: Cross multiply
    660.37x = 990.89 × 429.71
  4. Step 4: Simplify right side
    660.37x = 425,795.34
  5. Step 5: Solve for x
    x = 425,795.34/660.37
  6. Step 6: Final answer
    x = 644.78

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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.