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Finding the Fourth Proportional to 123.15, 169.68 and 90.36

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Solution

The fourth proportional to 123.15, 169.68 and 90.36 is: 124.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.15 : 169.68 = 90.36 : x
  2. Step 2: Convert to fraction form
    123.15/169.68 = 90.36/x
  3. Step 3: Cross multiply
    123.15x = 169.68 × 90.36
  4. Step 4: Simplify right side
    123.15x = 15,332.28
  5. Step 5: Solve for x
    x = 15,332.28/123.15
  6. Step 6: Final answer
    x = 124.50

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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.