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Finding the Fourth Proportional to 678.40, 935.31 and 553.84

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Solution

The fourth proportional to 678.40, 935.31 and 553.84 is: 763.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.40 : 935.31 = 553.84 : x
  2. Step 2: Convert to fraction form
    678.40/935.31 = 553.84/x
  3. Step 3: Cross multiply
    678.40x = 935.31 × 553.84
  4. Step 4: Simplify right side
    678.40x = 518,012.09
  5. Step 5: Solve for x
    x = 518,012.09/678.40
  6. Step 6: Final answer
    x = 763.58

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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.