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Finding the Fourth Proportional to 485.56, 670.16 and 289.05

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Solution

The fourth proportional to 485.56, 670.16 and 289.05 is: 398.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.56 : 670.16 = 289.05 : x
  2. Step 2: Convert to fraction form
    485.56/670.16 = 289.05/x
  3. Step 3: Cross multiply
    485.56x = 670.16 × 289.05
  4. Step 4: Simplify right side
    485.56x = 193,709.75
  5. Step 5: Solve for x
    x = 193,709.75/485.56
  6. Step 6: Final answer
    x = 398.94

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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.