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Finding the Fourth Proportional to 421.10, 631.07 and 215.23

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Solution

The fourth proportional to 421.10, 631.07 and 215.23 is: 322.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.10 : 631.07 = 215.23 : x
  2. Step 2: Convert to fraction form
    421.10/631.07 = 215.23/x
  3. Step 3: Cross multiply
    421.10x = 631.07 × 215.23
  4. Step 4: Simplify right side
    421.10x = 135,822.54
  5. Step 5: Solve for x
    x = 135,822.54/421.10
  6. Step 6: Final answer
    x = 322.55

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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.