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Finding the Fourth Proportional to 287.87, 397.47 and 221.37

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Solution

The fourth proportional to 287.87, 397.47 and 221.37 is: 305.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.87 : 397.47 = 221.37 : x
  2. Step 2: Convert to fraction form
    287.87/397.47 = 221.37/x
  3. Step 3: Cross multiply
    287.87x = 397.47 × 221.37
  4. Step 4: Simplify right side
    287.87x = 87,987.93
  5. Step 5: Solve for x
    x = 87,987.93/287.87
  6. Step 6: Final answer
    x = 305.66

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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.