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Finding the Fourth Proportional to 289.88, 434.40 and 221.18

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Solution

The fourth proportional to 289.88, 434.40 and 221.18 is: 331.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.88 : 434.40 = 221.18 : x
  2. Step 2: Convert to fraction form
    289.88/434.40 = 221.18/x
  3. Step 3: Cross multiply
    289.88x = 434.40 × 221.18
  4. Step 4: Simplify right side
    289.88x = 96,080.59
  5. Step 5: Solve for x
    x = 96,080.59/289.88
  6. Step 6: Final answer
    x = 331.45

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.