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Finding the Fourth Proportional to 123.57, 170.33 and 90.81

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Solution

The fourth proportional to 123.57, 170.33 and 90.81 is: 125.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.57 : 170.33 = 90.81 : x
  2. Step 2: Convert to fraction form
    123.57/170.33 = 90.81/x
  3. Step 3: Cross multiply
    123.57x = 170.33 × 90.81
  4. Step 4: Simplify right side
    123.57x = 15,467.21
  5. Step 5: Solve for x
    x = 15,467.21/123.57
  6. Step 6: Final answer
    x = 125.17

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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.