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Finding the Fourth Proportional to 305.95, 422.72 and 287.68

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Solution

The fourth proportional to 305.95, 422.72 and 287.68 is: 397.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    305.95 : 422.72 = 287.68 : x
  2. Step 2: Convert to fraction form
    305.95/422.72 = 287.68/x
  3. Step 3: Cross multiply
    305.95x = 422.72 × 287.68
  4. Step 4: Simplify right side
    305.95x = 121,608.09
  5. Step 5: Solve for x
    x = 121,608.09/305.95
  6. Step 6: Final answer
    x = 397.48

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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.