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Finding the Fourth Proportional to 485.45, 728.05 and 211.48

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Solution

The fourth proportional to 485.45, 728.05 and 211.48 is: 317.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.45 : 728.05 = 211.48 : x
  2. Step 2: Convert to fraction form
    485.45/728.05 = 211.48/x
  3. Step 3: Cross multiply
    485.45x = 728.05 × 211.48
  4. Step 4: Simplify right side
    485.45x = 153,965.67
  5. Step 5: Solve for x
    x = 153,965.67/485.45
  6. Step 6: Final answer
    x = 317.16

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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.