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Finding the Fourth Proportional to 386.12, 578.52 and 212.91

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Solution

The fourth proportional to 386.12, 578.52 and 212.91 is: 319.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.12 : 578.52 = 212.91 : x
  2. Step 2: Convert to fraction form
    386.12/578.52 = 212.91/x
  3. Step 3: Cross multiply
    386.12x = 578.52 × 212.91
  4. Step 4: Simplify right side
    386.12x = 123,172.69
  5. Step 5: Solve for x
    x = 123,172.69/386.12
  6. Step 6: Final answer
    x = 319.01

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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.