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Finding the Fourth Proportional to 386.19, 579.18 and 212.83

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Solution

The fourth proportional to 386.19, 579.18 and 212.83 is: 319.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.19 : 579.18 = 212.83 : x
  2. Step 2: Convert to fraction form
    386.19/579.18 = 212.83/x
  3. Step 3: Cross multiply
    386.19x = 579.18 × 212.83
  4. Step 4: Simplify right side
    386.19x = 123,264.43
  5. Step 5: Solve for x
    x = 123,264.43/386.19
  6. Step 6: Final answer
    x = 319.18

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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.