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Finding the Fourth Proportional to 387.10, 534.21 and 221.35

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Solution

The fourth proportional to 387.10, 534.21 and 221.35 is: 305.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.10 : 534.21 = 221.35 : x
  2. Step 2: Convert to fraction form
    387.10/534.21 = 221.35/x
  3. Step 3: Cross multiply
    387.10x = 534.21 × 221.35
  4. Step 4: Simplify right side
    387.10x = 118,244.71
  5. Step 5: Solve for x
    x = 118,244.71/387.10
  6. Step 6: Final answer
    x = 305.47

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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.