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Finding the Fourth Proportional to 1,390.08, 2,084.10 and 658.80

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Solution

The fourth proportional to 1,390.08, 2,084.10 and 658.80 is: 987.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,390.08 : 2,084.10 = 658.80 : x
  2. Step 2: Convert to fraction form
    1,390.08/2,084.10 = 658.80/x
  3. Step 3: Cross multiply
    1,390.08x = 2,084.10 × 658.80
  4. Step 4: Simplify right side
    1,390.08x = 1,373,005.08
  5. Step 5: Solve for x
    x = 1,373,005.08/1,390.08
  6. Step 6: Final answer
    x = 987.72

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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.