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Finding the Fourth Proportional to 678.46, 935.20 and 621.96

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Solution

The fourth proportional to 678.46, 935.20 and 621.96 is: 857.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.46 : 935.20 = 621.96 : x
  2. Step 2: Convert to fraction form
    678.46/935.20 = 621.96/x
  3. Step 3: Cross multiply
    678.46x = 935.20 × 621.96
  4. Step 4: Simplify right side
    678.46x = 581,656.99
  5. Step 5: Solve for x
    x = 581,656.99/678.46
  6. Step 6: Final answer
    x = 857.32

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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.