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Finding the Fourth Proportional to 485.39, 728.43 and 211.34

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Solution

The fourth proportional to 485.39, 728.43 and 211.34 is: 317.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.39 : 728.43 = 211.34 : x
  2. Step 2: Convert to fraction form
    485.39/728.43 = 211.34/x
  3. Step 3: Cross multiply
    485.39x = 728.43 × 211.34
  4. Step 4: Simplify right side
    485.39x = 153,945.34
  5. Step 5: Solve for x
    x = 153,945.34/485.39
  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.