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Finding the Fourth Proportional to 782.90, 1,080.39 and 451.40

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Solution

The fourth proportional to 782.90, 1,080.39 and 451.40 is: 622.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.90 : 1,080.39 = 451.40 : x
  2. Step 2: Convert to fraction form
    782.90/1,080.39 = 451.40/x
  3. Step 3: Cross multiply
    782.90x = 1,080.39 × 451.40
  4. Step 4: Simplify right side
    782.90x = 487,682.64
  5. Step 5: Solve for x
    x = 487,682.64/782.90
  6. Step 6: Final answer
    x = 622.92

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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.