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Finding the Fourth Proportional to 621.20, 857.63 and 411.56

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Solution

The fourth proportional to 621.20, 857.63 and 411.56 is: 568.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.20 : 857.63 = 411.56 : x
  2. Step 2: Convert to fraction form
    621.20/857.63 = 411.56/x
  3. Step 3: Cross multiply
    621.20x = 857.63 × 411.56
  4. Step 4: Simplify right side
    621.20x = 352,961.91
  5. Step 5: Solve for x
    x = 352,961.91/621.20
  6. Step 6: Final answer
    x = 568.20

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1.5x scale

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.