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Finding the Fourth Proportional to 621.78, 857.89 and 373.21

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Solution

The fourth proportional to 621.78, 857.89 and 373.21 is: 514.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.78 : 857.89 = 373.21 : x
  2. Step 2: Convert to fraction form
    621.78/857.89 = 373.21/x
  3. Step 3: Cross multiply
    621.78x = 857.89 × 373.21
  4. Step 4: Simplify right side
    621.78x = 320,171.45
  5. Step 5: Solve for x
    x = 320,171.45/621.78
  6. Step 6: Final answer
    x = 514.93

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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.