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Finding the Fourth Proportional to 678.98, 935.60 and 521.61

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Solution

The fourth proportional to 678.98, 935.60 and 521.61 is: 718.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.98 : 935.60 = 521.61 : x
  2. Step 2: Convert to fraction form
    678.98/935.60 = 521.61/x
  3. Step 3: Cross multiply
    678.98x = 935.60 × 521.61
  4. Step 4: Simplify right side
    678.98x = 488,012.20
  5. Step 5: Solve for x
    x = 488,012.20/678.98
  6. Step 6: Final answer
    x = 718.74

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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.