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Finding the Fourth Proportional to 265.90, 399 and 128.89

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Solution

The fourth proportional to 265.90, 399 and 128.89 is: 193.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    265.90 : 399 = 128.89 : x
  2. Step 2: Convert to fraction form
    265.90/399 = 128.89/x
  3. Step 3: Cross multiply
    265.90x = 399 × 128.89
  4. Step 4: Simplify right side
    265.90x = 51,427.11
  5. Step 5: Solve for x
    x = 51,427.11/265.90
  6. Step 6: Final answer
    x = 193.41

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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.