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Finding the Fourth Proportional to 485.21, 728.22 and 211.52

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Solution

The fourth proportional to 485.21, 728.22 and 211.52 is: 317.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.21 : 728.22 = 211.52 : x
  2. Step 2: Convert to fraction form
    485.21/728.22 = 211.52/x
  3. Step 3: Cross multiply
    485.21x = 728.22 × 211.52
  4. Step 4: Simplify right side
    485.21x = 154,029.45
  5. Step 5: Solve for x
    x = 154,029.45/485.21
  6. Step 6: Final answer
    x = 317.45

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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.