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Finding the Fourth Proportional to 421.80, 631.35 and 226.31

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Solution

The fourth proportional to 421.80, 631.35 and 226.31 is: 338.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.80 : 631.35 = 226.31 : x
  2. Step 2: Convert to fraction form
    421.80/631.35 = 226.31/x
  3. Step 3: Cross multiply
    421.80x = 631.35 × 226.31
  4. Step 4: Simplify right side
    421.80x = 142,880.82
  5. Step 5: Solve for x
    x = 142,880.82/421.80
  6. Step 6: Final answer
    x = 338.74

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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.