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Finding the Fourth Proportional to 275.39, 412.89 and 128.99

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Solution

The fourth proportional to 275.39, 412.89 and 128.99 is: 193.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    275.39 : 412.89 = 128.99 : x
  2. Step 2: Convert to fraction form
    275.39/412.89 = 128.99/x
  3. Step 3: Cross multiply
    275.39x = 412.89 × 128.99
  4. Step 4: Simplify right side
    275.39x = 53,256.62
  5. Step 5: Solve for x
    x = 53,256.62/275.39
  6. Step 6: Final answer
    x = 193.39

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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.