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Finding the Fourth Proportional to 421.61, 631.80 and 216.07

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Solution

The fourth proportional to 421.61, 631.80 and 216.07 is: 323.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.61 : 631.80 = 216.07 : x
  2. Step 2: Convert to fraction form
    421.61/631.80 = 216.07/x
  3. Step 3: Cross multiply
    421.61x = 631.80 × 216.07
  4. Step 4: Simplify right side
    421.61x = 136,511.45
  5. Step 5: Solve for x
    x = 136,511.45/421.61
  6. Step 6: Final answer
    x = 323.79

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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.