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Finding the Fourth Proportional to 485.51, 728.22 and 211.55

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Solution

The fourth proportional to 485.51, 728.22 and 211.55 is: 317.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.51 : 728.22 = 211.55 : x
  2. Step 2: Convert to fraction form
    485.51/728.22 = 211.55/x
  3. Step 3: Cross multiply
    485.51x = 728.22 × 211.55
  4. Step 4: Simplify right side
    485.51x = 154,054.94
  5. Step 5: Solve for x
    x = 154,054.94/485.51
  6. Step 6: Final answer
    x = 317.31

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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.