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Finding the Fourth Proportional to 420.05, 630.09 and 111.95

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Solution

The fourth proportional to 420.05, 630.09 and 111.95 is: 167.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.05 : 630.09 = 111.95 : x
  2. Step 2: Convert to fraction form
    420.05/630.09 = 111.95/x
  3. Step 3: Cross multiply
    420.05x = 630.09 × 111.95
  4. Step 4: Simplify right side
    420.05x = 70,535.43
  5. Step 5: Solve for x
    x = 70,535.43/420.05
  6. Step 6: Final answer
    x = 167.92

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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.