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Finding the Fourth Proportional to 265.47, 397.91 and 128.21

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Solution

The fourth proportional to 265.47, 397.91 and 128.21 is: 192.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    265.47 : 397.91 = 128.21 : x
  2. Step 2: Convert to fraction form
    265.47/397.91 = 128.21/x
  3. Step 3: Cross multiply
    265.47x = 397.91 × 128.21
  4. Step 4: Simplify right side
    265.47x = 51,015.49
  5. Step 5: Solve for x
    x = 51,015.49/265.47
  6. Step 6: Final answer
    x = 192.17

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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.