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Finding the Fourth Proportional to 386.64, 578.94 and 212.49

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Solution

The fourth proportional to 386.64, 578.94 and 212.49 is: 318.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.64 : 578.94 = 212.49 : x
  2. Step 2: Convert to fraction form
    386.64/578.94 = 212.49/x
  3. Step 3: Cross multiply
    386.64x = 578.94 × 212.49
  4. Step 4: Simplify right side
    386.64x = 123,018.96
  5. Step 5: Solve for x
    x = 123,018.96/386.64
  6. Step 6: Final answer
    x = 318.17

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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.