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Finding the Fourth Proportional to 1,387.94, 2,081.09 and 658.13

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Solution

The fourth proportional to 1,387.94, 2,081.09 and 658.13 is: 986.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,387.94 : 2,081.09 = 658.13 : x
  2. Step 2: Convert to fraction form
    1,387.94/2,081.09 = 658.13/x
  3. Step 3: Cross multiply
    1,387.94x = 2,081.09 × 658.13
  4. Step 4: Simplify right side
    1,387.94x = 1,369,619.00
  5. Step 5: Solve for x
    x = 1,369,619.00/1,387.94
  6. Step 6: Final answer
    x = 986.80

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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.