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Finding the Fourth Proportional to 678.28, 1,016.60 and 485.50

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Solution

The fourth proportional to 678.28, 1,016.60 and 485.50 is: 727.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.28 : 1,016.60 = 485.50 : x
  2. Step 2: Convert to fraction form
    678.28/1,016.60 = 485.50/x
  3. Step 3: Cross multiply
    678.28x = 1,016.60 × 485.50
  4. Step 4: Simplify right side
    678.28x = 493,559.30
  5. Step 5: Solve for x
    x = 493,559.30/678.28
  6. Step 6: Final answer
    x = 727.66

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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.