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Finding the Fourth Proportional to 678.43, 935.93 and 520.78

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Solution

The fourth proportional to 678.43, 935.93 and 520.78 is: 718.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.43 : 935.93 = 520.78 : x
  2. Step 2: Convert to fraction form
    678.43/935.93 = 520.78/x
  3. Step 3: Cross multiply
    678.43x = 935.93 × 520.78
  4. Step 4: Simplify right side
    678.43x = 487,412.88
  5. Step 5: Solve for x
    x = 487,412.88/678.43
  6. Step 6: Final answer
    x = 718.45

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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.