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Finding the Fourth Proportional to 1,389.30, 2,084.97 and 658.87

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Solution

The fourth proportional to 1,389.30, 2,084.97 and 658.87 is: 988.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.30 : 2,084.97 = 658.87 : x
  2. Step 2: Convert to fraction form
    1,389.30/2,084.97 = 658.87/x
  3. Step 3: Cross multiply
    1,389.30x = 2,084.97 × 658.87
  4. Step 4: Simplify right side
    1,389.30x = 1,373,724.18
  5. Step 5: Solve for x
    x = 1,373,724.18/1,389.30
  6. Step 6: Final answer
    x = 988.79

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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.