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Finding the Fourth Proportional to 455.70, 680.23 and 421.89

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Solution

The fourth proportional to 455.70, 680.23 and 421.89 is: 629.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    455.70 : 680.23 = 421.89 : x
  2. Step 2: Convert to fraction form
    455.70/680.23 = 421.89/x
  3. Step 3: Cross multiply
    455.70x = 680.23 × 421.89
  4. Step 4: Simplify right side
    455.70x = 286,982.23
  5. Step 5: Solve for x
    x = 286,982.23/455.70
  6. Step 6: Final answer
    x = 629.76

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.