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Finding the Fourth Proportional to 787, 1,085.92 and 455.47

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Solution

The fourth proportional to 787, 1,085.92 and 455.47 is: 628.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    787 : 1,085.92 = 455.47 : x
  2. Step 2: Convert to fraction form
    787/1,085.92 = 455.47/x
  3. Step 3: Cross multiply
    787x = 1,085.92 × 455.47
  4. Step 4: Simplify right side
    787x = 494,603.98
  5. Step 5: Solve for x
    x = 494,603.98/787
  6. Step 6: Final answer
    x = 628.47

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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.