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Finding the Fourth Proportional to 668.20, 920.82 and 621.22

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Solution

The fourth proportional to 668.20, 920.82 and 621.22 is: 856.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.20 : 920.82 = 621.22 : x
  2. Step 2: Convert to fraction form
    668.20/920.82 = 621.22/x
  3. Step 3: Cross multiply
    668.20x = 920.82 × 621.22
  4. Step 4: Simplify right side
    668.20x = 572,031.80
  5. Step 5: Solve for x
    x = 572,031.80/668.20
  6. Step 6: Final answer
    x = 856.08

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.