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Finding the Fourth Proportional to 491.38, 736.80 and 217.20

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Solution

The fourth proportional to 491.38, 736.80 and 217.20 is: 325.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    491.38 : 736.80 = 217.20 : x
  2. Step 2: Convert to fraction form
    491.38/736.80 = 217.20/x
  3. Step 3: Cross multiply
    491.38x = 736.80 × 217.20
  4. Step 4: Simplify right side
    491.38x = 160,032.96
  5. Step 5: Solve for x
    x = 160,032.96/491.38
  6. Step 6: Final answer
    x = 325.68

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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.