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Finding the Fourth Proportional to 660.54, 989.70 and 429.09

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Solution

The fourth proportional to 660.54, 989.70 and 429.09 is: 642.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.54 : 989.70 = 429.09 : x
  2. Step 2: Convert to fraction form
    660.54/989.70 = 429.09/x
  3. Step 3: Cross multiply
    660.54x = 989.70 × 429.09
  4. Step 4: Simplify right side
    660.54x = 424,670.37
  5. Step 5: Solve for x
    x = 424,670.37/660.54
  6. Step 6: Final answer
    x = 642.91

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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.