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Finding the Fourth Proportional to 86.96, 120.04 and 65.20

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Solution

The fourth proportional to 86.96, 120.04 and 65.20 is: 90.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.96 : 120.04 = 65.20 : x
  2. Step 2: Convert to fraction form
    86.96/120.04 = 65.20/x
  3. Step 3: Cross multiply
    86.96x = 120.04 × 65.20
  4. Step 4: Simplify right side
    86.96x = 7,826.61
  5. Step 5: Solve for x
    x = 7,826.61/86.96
  6. Step 6: Final answer
    x = 90.00

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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.