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Finding the Fourth Proportional to 680.90, 1,021.45 and 270.08

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Solution

The fourth proportional to 680.90, 1,021.45 and 270.08 is: 405.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.90 : 1,021.45 = 270.08 : x
  2. Step 2: Convert to fraction form
    680.90/1,021.45 = 270.08/x
  3. Step 3: Cross multiply
    680.90x = 1,021.45 × 270.08
  4. Step 4: Simplify right side
    680.90x = 275,876.11
  5. Step 5: Solve for x
    x = 275,876.11/680.90
  6. Step 6: Final answer
    x = 405.16

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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.