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Finding the Fourth Proportional to 421.25, 630.76 and 338.58

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Solution

The fourth proportional to 421.25, 630.76 and 338.58 is: 506.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.25 : 630.76 = 338.58 : x
  2. Step 2: Convert to fraction form
    421.25/630.76 = 338.58/x
  3. Step 3: Cross multiply
    421.25x = 630.76 × 338.58
  4. Step 4: Simplify right side
    421.25x = 213,563.46
  5. Step 5: Solve for x
    x = 213,563.46/421.25
  6. Step 6: Final answer
    x = 506.97

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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.