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Finding the Fourth Proportional to 312.90, 431.94 and 188.65

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Solution

The fourth proportional to 312.90, 431.94 and 188.65 is: 260.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.90 : 431.94 = 188.65 : x
  2. Step 2: Convert to fraction form
    312.90/431.94 = 188.65/x
  3. Step 3: Cross multiply
    312.90x = 431.94 × 188.65
  4. Step 4: Simplify right side
    312.90x = 81,485.48
  5. Step 5: Solve for x
    x = 81,485.48/312.90
  6. Step 6: Final answer
    x = 260.42

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.