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Finding the Fourth Proportional to 84.90, 126.54 and 83.07

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Solution

The fourth proportional to 84.90, 126.54 and 83.07 is: 123.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.90 : 126.54 = 83.07 : x
  2. Step 2: Convert to fraction form
    84.90/126.54 = 83.07/x
  3. Step 3: Cross multiply
    84.90x = 126.54 × 83.07
  4. Step 4: Simplify right side
    84.90x = 10,511.26
  5. Step 5: Solve for x
    x = 10,511.26/84.90
  6. Step 6: Final answer
    x = 123.81

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.