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Finding the Fourth Proportional to 1,208.21, 1,812.32 and 660.85

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Solution

The fourth proportional to 1,208.21, 1,812.32 and 660.85 is: 991.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,208.21 : 1,812.32 = 660.85 : x
  2. Step 2: Convert to fraction form
    1,208.21/1,812.32 = 660.85/x
  3. Step 3: Cross multiply
    1,208.21x = 1,812.32 × 660.85
  4. Step 4: Simplify right side
    1,208.21x = 1,197,671.67
  5. Step 5: Solve for x
    x = 1,197,671.67/1,208.21
  6. Step 6: Final answer
    x = 991.28

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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.