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Finding the Fourth Proportional to 387.30, 534.47 and 221.49

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Solution

The fourth proportional to 387.30, 534.47 and 221.49 is: 305.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.30 : 534.47 = 221.49 : x
  2. Step 2: Convert to fraction form
    387.30/534.47 = 221.49/x
  3. Step 3: Cross multiply
    387.30x = 534.47 × 221.49
  4. Step 4: Simplify right side
    387.30x = 118,379.50
  5. Step 5: Solve for x
    x = 118,379.50/387.30
  6. Step 6: Final answer
    x = 305.65

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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.