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Finding the Fourth Proportional to 421.52, 630.99 and 380.21

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Solution

The fourth proportional to 421.52, 630.99 and 380.21 is: 569.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.52 : 630.99 = 380.21 : x
  2. Step 2: Convert to fraction form
    421.52/630.99 = 380.21/x
  3. Step 3: Cross multiply
    421.52x = 630.99 × 380.21
  4. Step 4: Simplify right side
    421.52x = 239,905.55
  5. Step 5: Solve for x
    x = 239,905.55/421.52
  6. Step 6: Final answer
    x = 569.15

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.