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Finding the Fourth Proportional to 840.76, 1,261.22 and 378.74

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Solution

The fourth proportional to 840.76, 1,261.22 and 378.74 is: 568.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.76 : 1,261.22 = 378.74 : x
  2. Step 2: Convert to fraction form
    840.76/1,261.22 = 378.74/x
  3. Step 3: Cross multiply
    840.76x = 1,261.22 × 378.74
  4. Step 4: Simplify right side
    840.76x = 477,674.46
  5. Step 5: Solve for x
    x = 477,674.46/840.76
  6. Step 6: Final answer
    x = 568.15

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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.