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Finding the Fourth Proportional to 327.81, 491.78 and 145.21

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Solution

The fourth proportional to 327.81, 491.78 and 145.21 is: 217.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    327.81 : 491.78 = 145.21 : x
  2. Step 2: Convert to fraction form
    327.81/491.78 = 145.21/x
  3. Step 3: Cross multiply
    327.81x = 491.78 × 145.21
  4. Step 4: Simplify right side
    327.81x = 71,411.37
  5. Step 5: Solve for x
    x = 71,411.37/327.81
  6. Step 6: Final answer
    x = 217.84

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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.