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Finding the Fourth Proportional to 387.49, 534.71 and 221.71

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Solution

The fourth proportional to 387.49, 534.71 and 221.71 is: 305.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.49 : 534.71 = 221.71 : x
  2. Step 2: Convert to fraction form
    387.49/534.71 = 221.71/x
  3. Step 3: Cross multiply
    387.49x = 534.71 × 221.71
  4. Step 4: Simplify right side
    387.49x = 118,546.77
  5. Step 5: Solve for x
    x = 118,546.77/387.49
  6. Step 6: Final answer
    x = 305.93

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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.