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Finding the Fourth Proportional to 485.40, 727.83 and 427.77

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Solution

The fourth proportional to 485.40, 727.83 and 427.77 is: 641.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.40 : 727.83 = 427.77 : x
  2. Step 2: Convert to fraction form
    485.40/727.83 = 427.77/x
  3. Step 3: Cross multiply
    485.40x = 727.83 × 427.77
  4. Step 4: Simplify right side
    485.40x = 311,343.84
  5. Step 5: Solve for x
    x = 311,343.84/485.40
  6. Step 6: Final answer
    x = 641.42

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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.