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Finding the Fourth Proportional to 103.51, 142.52 and 90.57

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Solution

The fourth proportional to 103.51, 142.52 and 90.57 is: 124.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.51 : 142.52 = 90.57 : x
  2. Step 2: Convert to fraction form
    103.51/142.52 = 90.57/x
  3. Step 3: Cross multiply
    103.51x = 142.52 × 90.57
  4. Step 4: Simplify right side
    103.51x = 12,907.58
  5. Step 5: Solve for x
    x = 12,907.58/103.51
  6. Step 6: Final answer
    x = 124.70

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.