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Finding the Fourth Proportional to 811.72, 1,216.68 and 400.76

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Solution

The fourth proportional to 811.72, 1,216.68 and 400.76 is: 600.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.72 : 1,216.68 = 400.76 : x
  2. Step 2: Convert to fraction form
    811.72/1,216.68 = 400.76/x
  3. Step 3: Cross multiply
    811.72x = 1,216.68 × 400.76
  4. Step 4: Simplify right side
    811.72x = 487,596.68
  5. Step 5: Solve for x
    x = 487,596.68/811.72
  6. Step 6: Final answer
    x = 600.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.