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Finding the Fourth Proportional to 660.95, 989.09 and 487.21

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Solution

The fourth proportional to 660.95, 989.09 and 487.21 is: 729.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.95 : 989.09 = 487.21 : x
  2. Step 2: Convert to fraction form
    660.95/989.09 = 487.21/x
  3. Step 3: Cross multiply
    660.95x = 989.09 × 487.21
  4. Step 4: Simplify right side
    660.95x = 481,887.16
  5. Step 5: Solve for x
    x = 481,887.16/660.95
  6. Step 6: Final answer
    x = 729.08

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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.