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Finding the Fourth Proportional to 123.61, 170.40 and 86.66

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Solution

The fourth proportional to 123.61, 170.40 and 86.66 is: 119.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.61 : 170.40 = 86.66 : x
  2. Step 2: Convert to fraction form
    123.61/170.40 = 86.66/x
  3. Step 3: Cross multiply
    123.61x = 170.40 × 86.66
  4. Step 4: Simplify right side
    123.61x = 14,766.01
  5. Step 5: Solve for x
    x = 14,766.01/123.61
  6. Step 6: Final answer
    x = 119.46

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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.