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Finding the Fourth Proportional to 421.09, 631.11 and 215.54

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Solution

The fourth proportional to 421.09, 631.11 and 215.54 is: 323.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.09 : 631.11 = 215.54 : x
  2. Step 2: Convert to fraction form
    421.09/631.11 = 215.54/x
  3. Step 3: Cross multiply
    421.09x = 631.11 × 215.54
  4. Step 4: Simplify right side
    421.09x = 136,029.47
  5. Step 5: Solve for x
    x = 136,029.47/421.09
  6. Step 6: Final answer
    x = 323.04

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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.