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Finding the Fourth Proportional to 782.52, 1,081.26 and 644.28

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Solution

The fourth proportional to 782.52, 1,081.26 and 644.28 is: 890.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.52 : 1,081.26 = 644.28 : x
  2. Step 2: Convert to fraction form
    782.52/1,081.26 = 644.28/x
  3. Step 3: Cross multiply
    782.52x = 1,081.26 × 644.28
  4. Step 4: Simplify right side
    782.52x = 696,634.19
  5. Step 5: Solve for x
    x = 696,634.19/782.52
  6. Step 6: Final answer
    x = 890.24

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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.