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Finding the Fourth Proportional to 420.38, 629.75 and 275.66

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Solution

The fourth proportional to 420.38, 629.75 and 275.66 is: 412.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.38 : 629.75 = 275.66 : x
  2. Step 2: Convert to fraction form
    420.38/629.75 = 275.66/x
  3. Step 3: Cross multiply
    420.38x = 629.75 × 275.66
  4. Step 4: Simplify right side
    420.38x = 173,595.51
  5. Step 5: Solve for x
    x = 173,595.51/420.38
  6. Step 6: Final answer
    x = 412.95

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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.