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Finding the Fourth Proportional to 783.17, 1,079.76 and 487.91

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Solution

The fourth proportional to 783.17, 1,079.76 and 487.91 is: 672.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.17 : 1,079.76 = 487.91 : x
  2. Step 2: Convert to fraction form
    783.17/1,079.76 = 487.91/x
  3. Step 3: Cross multiply
    783.17x = 1,079.76 × 487.91
  4. Step 4: Simplify right side
    783.17x = 526,825.70
  5. Step 5: Solve for x
    x = 526,825.70/783.17
  6. Step 6: Final answer
    x = 672.68

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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.