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Finding the Fourth Proportional to 811.72, 1,120.71 and 624.88

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Solution

The fourth proportional to 811.72, 1,120.71 and 624.88 is: 862.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.72 : 1,120.71 = 624.88 : x
  2. Step 2: Convert to fraction form
    811.72/1,120.71 = 624.88/x
  3. Step 3: Cross multiply
    811.72x = 1,120.71 × 624.88
  4. Step 4: Simplify right side
    811.72x = 700,306.46
  5. Step 5: Solve for x
    x = 700,306.46/811.72
  6. Step 6: Final answer
    x = 862.75

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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.