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Finding the Fourth Proportional to 86.69, 129.91 and 79.01

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Solution

The fourth proportional to 86.69, 129.91 and 79.01 is: 118.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.69 : 129.91 = 79.01 : x
  2. Step 2: Convert to fraction form
    86.69/129.91 = 79.01/x
  3. Step 3: Cross multiply
    86.69x = 129.91 × 79.01
  4. Step 4: Simplify right side
    86.69x = 10,263.98
  5. Step 5: Solve for x
    x = 10,263.98/86.69
  6. Step 6: Final answer
    x = 118.40

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.