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Finding the Fourth Proportional to 421.63, 631.49 and 215.82

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Solution

The fourth proportional to 421.63, 631.49 and 215.82 is: 323.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.63 : 631.49 = 215.82 : x
  2. Step 2: Convert to fraction form
    421.63/631.49 = 215.82/x
  3. Step 3: Cross multiply
    421.63x = 631.49 × 215.82
  4. Step 4: Simplify right side
    421.63x = 136,287.09
  5. Step 5: Solve for x
    x = 136,287.09/421.63
  6. Step 6: Final answer
    x = 323.24

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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.