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Finding the Fourth Proportional to 1,379.12, 2,065.32 and 648.90

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Solution

The fourth proportional to 1,379.12, 2,065.32 and 648.90 is: 971.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.12 : 2,065.32 = 648.90 : x
  2. Step 2: Convert to fraction form
    1,379.12/2,065.32 = 648.90/x
  3. Step 3: Cross multiply
    1,379.12x = 2,065.32 × 648.90
  4. Step 4: Simplify right side
    1,379.12x = 1,340,186.15
  5. Step 5: Solve for x
    x = 1,340,186.15/1,379.12
  6. Step 6: Final answer
    x = 971.77

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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.