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Finding the Fourth Proportional to 387.12, 534.12 and 221.34

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Solution

The fourth proportional to 387.12, 534.12 and 221.34 is: 305.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.12 : 534.12 = 221.34 : x
  2. Step 2: Convert to fraction form
    387.12/534.12 = 221.34/x
  3. Step 3: Cross multiply
    387.12x = 534.12 × 221.34
  4. Step 4: Simplify right side
    387.12x = 118,222.12
  5. Step 5: Solve for x
    x = 118,222.12/387.12
  6. Step 6: Final answer
    x = 305.39

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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.