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Finding the Fourth Proportional to 1,107, 1,527.72 and 641.40

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Solution

The fourth proportional to 1,107, 1,527.72 and 641.40 is: 885.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,107 : 1,527.72 = 641.40 : x
  2. Step 2: Convert to fraction form
    1,107/1,527.72 = 641.40/x
  3. Step 3: Cross multiply
    1,107x = 1,527.72 × 641.40
  4. Step 4: Simplify right side
    1,107x = 979,879.61
  5. Step 5: Solve for x
    x = 979,879.61/1,107
  6. Step 6: Final answer
    x = 885.17

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.