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Finding the Fourth Proportional to 421.45, 632.08 and 215.76

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Solution

The fourth proportional to 421.45, 632.08 and 215.76 is: 323.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.45 : 632.08 = 215.76 : x
  2. Step 2: Convert to fraction form
    421.45/632.08 = 215.76/x
  3. Step 3: Cross multiply
    421.45x = 632.08 × 215.76
  4. Step 4: Simplify right side
    421.45x = 136,377.58
  5. Step 5: Solve for x
    x = 136,377.58/421.45
  6. Step 6: Final answer
    x = 323.59

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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.