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Finding the Fourth Proportional to 265.40, 398.23 and 128.56

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Solution

The fourth proportional to 265.40, 398.23 and 128.56 is: 192.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    265.40 : 398.23 = 128.56 : x
  2. Step 2: Convert to fraction form
    265.40/398.23 = 128.56/x
  3. Step 3: Cross multiply
    265.40x = 398.23 × 128.56
  4. Step 4: Simplify right side
    265.40x = 51,196.45
  5. Step 5: Solve for x
    x = 51,196.45/265.40
  6. Step 6: Final answer
    x = 192.90

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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.