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Finding the Fourth Proportional to 102.93, 142.29 and 86.55

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Solution

The fourth proportional to 102.93, 142.29 and 86.55 is: 119.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.93 : 142.29 = 86.55 : x
  2. Step 2: Convert to fraction form
    102.93/142.29 = 86.55/x
  3. Step 3: Cross multiply
    102.93x = 142.29 × 86.55
  4. Step 4: Simplify right side
    102.93x = 12,315.20
  5. Step 5: Solve for x
    x = 12,315.20/102.93
  6. Step 6: Final answer
    x = 119.65

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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.