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Finding the Fourth Proportional to 305.12, 420.67 and 281.65

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Solution

The fourth proportional to 305.12, 420.67 and 281.65 is: 388.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.12 : 420.67 = 281.65 : x
  2. Step 2: Convert to fraction form
    305.12/420.67 = 281.65/x
  3. Step 3: Cross multiply
    305.12x = 420.67 × 281.65
  4. Step 4: Simplify right side
    305.12x = 118,481.71
  5. Step 5: Solve for x
    x = 118,481.71/305.12
  6. Step 6: Final answer
    x = 388.31

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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.