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Finding the Fourth Proportional to 287.65, 397.15 and 221.14

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Solution

The fourth proportional to 287.65, 397.15 and 221.14 is: 305.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.65 : 397.15 = 221.14 : x
  2. Step 2: Convert to fraction form
    287.65/397.15 = 221.14/x
  3. Step 3: Cross multiply
    287.65x = 397.15 × 221.14
  4. Step 4: Simplify right side
    287.65x = 87,827.56
  5. Step 5: Solve for x
    x = 87,827.56/287.65
  6. Step 6: Final answer
    x = 305.33

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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.