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Finding the Fourth Proportional to 678.06, 935.57 and 398.28

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Solution

The fourth proportional to 678.06, 935.57 and 398.28 is: 549.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.06 : 935.57 = 398.28 : x
  2. Step 2: Convert to fraction form
    678.06/935.57 = 398.28/x
  3. Step 3: Cross multiply
    678.06x = 935.57 × 398.28
  4. Step 4: Simplify right side
    678.06x = 372,618.82
  5. Step 5: Solve for x
    x = 372,618.82/678.06
  6. Step 6: Final answer
    x = 549.54

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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.