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Finding the Fourth Proportional to 1,389.48, 2,083.91 and 658.65

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Solution

The fourth proportional to 1,389.48, 2,083.91 and 658.65 is: 987.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.48 : 2,083.91 = 658.65 : x
  2. Step 2: Convert to fraction form
    1,389.48/2,083.91 = 658.65/x
  3. Step 3: Cross multiply
    1,389.48x = 2,083.91 × 658.65
  4. Step 4: Simplify right side
    1,389.48x = 1,372,567.32
  5. Step 5: Solve for x
    x = 1,372,567.32/1,389.48
  6. Step 6: Final answer
    x = 987.83

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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.