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Finding the Fourth Proportional to 265.30, 397.80 and 128.38

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Solution

The fourth proportional to 265.30, 397.80 and 128.38 is: 192.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    265.30 : 397.80 = 128.38 : x
  2. Step 2: Convert to fraction form
    265.30/397.80 = 128.38/x
  3. Step 3: Cross multiply
    265.30x = 397.80 × 128.38
  4. Step 4: Simplify right side
    265.30x = 51,069.56
  5. Step 5: Solve for x
    x = 51,069.56/265.30
  6. Step 6: Final answer
    x = 192.50

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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.