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Finding the Fourth Proportional to 385.76, 578.39 and 212.51

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Solution

The fourth proportional to 385.76, 578.39 and 212.51 is: 318.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.76 : 578.39 = 212.51 : x
  2. Step 2: Convert to fraction form
    385.76/578.39 = 212.51/x
  3. Step 3: Cross multiply
    385.76x = 578.39 × 212.51
  4. Step 4: Simplify right side
    385.76x = 122,914.64
  5. Step 5: Solve for x
    x = 122,914.64/385.76
  6. Step 6: Final answer
    x = 318.63

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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.