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Finding the Fourth Proportional to 485.72, 728.57 and 120.51

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Solution

The fourth proportional to 485.72, 728.57 and 120.51 is: 180.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.72 : 728.57 = 120.51 : x
  2. Step 2: Convert to fraction form
    485.72/728.57 = 120.51/x
  3. Step 3: Cross multiply
    485.72x = 728.57 × 120.51
  4. Step 4: Simplify right side
    485.72x = 87,799.97
  5. Step 5: Solve for x
    x = 87,799.97/485.72
  6. Step 6: Final answer
    x = 180.76

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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.