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Finding the Fourth Proportional to 342.09, 513.13 and 85.59

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Solution

The fourth proportional to 342.09, 513.13 and 85.59 is: 128.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    342.09 : 513.13 = 85.59 : x
  2. Step 2: Convert to fraction form
    342.09/513.13 = 85.59/x
  3. Step 3: Cross multiply
    342.09x = 513.13 × 85.59
  4. Step 4: Simplify right side
    342.09x = 43,918.37
  5. Step 5: Solve for x
    x = 43,918.37/342.09
  6. Step 6: Final answer
    x = 128.38

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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.