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Finding the Fourth Proportional to 420.18, 629.90 and 163.50

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Solution

The fourth proportional to 420.18, 629.90 and 163.50 is: 245.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.18 : 629.90 = 163.50 : x
  2. Step 2: Convert to fraction form
    420.18/629.90 = 163.50/x
  3. Step 3: Cross multiply
    420.18x = 629.90 × 163.50
  4. Step 4: Simplify right side
    420.18x = 102,988.65
  5. Step 5: Solve for x
    x = 102,988.65/420.18
  6. Step 6: Final answer
    x = 245.11

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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.