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Finding the Fourth Proportional to 1,188.87, 1,640.64 and 664.89

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Solution

The fourth proportional to 1,188.87, 1,640.64 and 664.89 is: 917.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,188.87 : 1,640.64 = 664.89 : x
  2. Step 2: Convert to fraction form
    1,188.87/1,640.64 = 664.89/x
  3. Step 3: Cross multiply
    1,188.87x = 1,640.64 × 664.89
  4. Step 4: Simplify right side
    1,188.87x = 1,090,845.13
  5. Step 5: Solve for x
    x = 1,090,845.13/1,188.87
  6. Step 6: Final answer
    x = 917.55

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.