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Finding the Fourth Proportional to 811.56, 1,216.56 and 378.96

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Solution

The fourth proportional to 811.56, 1,216.56 and 378.96 is: 568.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.56 : 1,216.56 = 378.96 : x
  2. Step 2: Convert to fraction form
    811.56/1,216.56 = 378.96/x
  3. Step 3: Cross multiply
    811.56x = 1,216.56 × 378.96
  4. Step 4: Simplify right side
    811.56x = 461,027.58
  5. Step 5: Solve for x
    x = 461,027.58/811.56
  6. Step 6: Final answer
    x = 568.08

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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.