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Finding the Fourth Proportional to 786.87, 1,085.72 and 455.07

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Solution

The fourth proportional to 786.87, 1,085.72 and 455.07 is: 627.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.87 : 1,085.72 = 455.07 : x
  2. Step 2: Convert to fraction form
    786.87/1,085.72 = 455.07/x
  3. Step 3: Cross multiply
    786.87x = 1,085.72 × 455.07
  4. Step 4: Simplify right side
    786.87x = 494,078.60
  5. Step 5: Solve for x
    x = 494,078.60/786.87
  6. Step 6: Final answer
    x = 627.90

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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.