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Finding the Fourth Proportional to 485.30, 728.06 and 211.42

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Solution

The fourth proportional to 485.30, 728.06 and 211.42 is: 317.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.30 : 728.06 = 211.42 : x
  2. Step 2: Convert to fraction form
    485.30/728.06 = 211.42/x
  3. Step 3: Cross multiply
    485.30x = 728.06 × 211.42
  4. Step 4: Simplify right side
    485.30x = 153,926.45
  5. Step 5: Solve for x
    x = 153,926.45/485.30
  6. Step 6: Final answer
    x = 317.18

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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.