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Finding the Fourth Proportional to 485.64, 728.64 and 225.78

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Solution

The fourth proportional to 485.64, 728.64 and 225.78 is: 338.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.64 : 728.64 = 225.78 : x
  2. Step 2: Convert to fraction form
    485.64/728.64 = 225.78/x
  3. Step 3: Cross multiply
    485.64x = 728.64 × 225.78
  4. Step 4: Simplify right side
    485.64x = 164,512.34
  5. Step 5: Solve for x
    x = 164,512.34/485.64
  6. Step 6: Final answer
    x = 338.75

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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.