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Finding the Fourth Proportional to 287.72, 397.18 and 189.51

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Solution

The fourth proportional to 287.72, 397.18 and 189.51 is: 261.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.72 : 397.18 = 189.51 : x
  2. Step 2: Convert to fraction form
    287.72/397.18 = 189.51/x
  3. Step 3: Cross multiply
    287.72x = 397.18 × 189.51
  4. Step 4: Simplify right side
    287.72x = 75,269.58
  5. Step 5: Solve for x
    x = 75,269.58/287.72
  6. Step 6: Final answer
    x = 261.61

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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.