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Finding the Fourth Proportional to 621.21, 857.99 and 511.05

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Solution

The fourth proportional to 621.21, 857.99 and 511.05 is: 705.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.21 : 857.99 = 511.05 : x
  2. Step 2: Convert to fraction form
    621.21/857.99 = 511.05/x
  3. Step 3: Cross multiply
    621.21x = 857.99 × 511.05
  4. Step 4: Simplify right side
    621.21x = 438,475.79
  5. Step 5: Solve for x
    x = 438,475.79/621.21
  6. Step 6: Final answer
    x = 705.84

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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.