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Finding the Fourth Proportional to 451.90, 678.20 and 208.60

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Solution

The fourth proportional to 451.90, 678.20 and 208.60 is: 313.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    451.90 : 678.20 = 208.60 : x
  2. Step 2: Convert to fraction form
    451.90/678.20 = 208.60/x
  3. Step 3: Cross multiply
    451.90x = 678.20 × 208.60
  4. Step 4: Simplify right side
    451.90x = 141,472.52
  5. Step 5: Solve for x
    x = 141,472.52/451.90
  6. Step 6: Final answer
    x = 313.06

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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.