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Finding the Fourth Proportional to 678.56, 1,015.50 and 418.46

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Solution

The fourth proportional to 678.56, 1,015.50 and 418.46 is: 626.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.56 : 1,015.50 = 418.46 : x
  2. Step 2: Convert to fraction form
    678.56/1,015.50 = 418.46/x
  3. Step 3: Cross multiply
    678.56x = 1,015.50 × 418.46
  4. Step 4: Simplify right side
    678.56x = 424,946.13
  5. Step 5: Solve for x
    x = 424,946.13/678.56
  6. Step 6: Final answer
    x = 626.25

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.