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Finding the Fourth Proportional to 345.39, 518.07 and 128.95

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Solution

The fourth proportional to 345.39, 518.07 and 128.95 is: 193.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    345.39 : 518.07 = 128.95 : x
  2. Step 2: Convert to fraction form
    345.39/518.07 = 128.95/x
  3. Step 3: Cross multiply
    345.39x = 518.07 × 128.95
  4. Step 4: Simplify right side
    345.39x = 66,806.87
  5. Step 5: Solve for x
    x = 66,806.87/345.39
  6. Step 6: Final answer
    x = 193.42

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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.