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Finding the Fourth Proportional to 387.44, 534.69 and 221.70

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Solution

The fourth proportional to 387.44, 534.69 and 221.70 is: 305.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.44 : 534.69 = 221.70 : x
  2. Step 2: Convert to fraction form
    387.44/534.69 = 221.70/x
  3. Step 3: Cross multiply
    387.44x = 534.69 × 221.70
  4. Step 4: Simplify right side
    387.44x = 118,539.66
  5. Step 5: Solve for x
    x = 118,539.66/387.44
  6. Step 6: Final answer
    x = 305.96

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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.