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Finding the Fourth Proportional to 485.57, 728.40 and 193.16

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Solution

The fourth proportional to 485.57, 728.40 and 193.16 is: 289.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.57 : 728.40 = 193.16 : x
  2. Step 2: Convert to fraction form
    485.57/728.40 = 193.16/x
  3. Step 3: Cross multiply
    485.57x = 728.40 × 193.16
  4. Step 4: Simplify right side
    485.57x = 140,697.74
  5. Step 5: Solve for x
    x = 140,697.74/485.57
  6. Step 6: Final answer
    x = 289.76

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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.