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Finding the Fourth Proportional to 285.47, 428.21 and 163.81

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Solution

The fourth proportional to 285.47, 428.21 and 163.81 is: 245.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.47 : 428.21 = 163.81 : x
  2. Step 2: Convert to fraction form
    285.47/428.21 = 163.81/x
  3. Step 3: Cross multiply
    285.47x = 428.21 × 163.81
  4. Step 4: Simplify right side
    285.47x = 70,144.26
  5. Step 5: Solve for x
    x = 70,144.26/285.47
  6. Step 6: Final answer
    x = 245.72

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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.