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Finding the Fourth Proportional to 378.86, 522.81 and 221.53

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Solution

The fourth proportional to 378.86, 522.81 and 221.53 is: 305.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.86 : 522.81 = 221.53 : x
  2. Step 2: Convert to fraction form
    378.86/522.81 = 221.53/x
  3. Step 3: Cross multiply
    378.86x = 522.81 × 221.53
  4. Step 4: Simplify right side
    378.86x = 115,818.10
  5. Step 5: Solve for x
    x = 115,818.10/378.86
  6. Step 6: Final answer
    x = 305.70

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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.