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Finding the Fourth Proportional to 421.78, 632.24 and 161.71

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Solution

The fourth proportional to 421.78, 632.24 and 161.71 is: 242.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.78 : 632.24 = 161.71 : x
  2. Step 2: Convert to fraction form
    421.78/632.24 = 161.71/x
  3. Step 3: Cross multiply
    421.78x = 632.24 × 161.71
  4. Step 4: Simplify right side
    421.78x = 102,237.14
  5. Step 5: Solve for x
    x = 102,237.14/421.78
  6. Step 6: Final answer
    x = 242.40

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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.