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Finding the Fourth Proportional to 86.99, 130.96 and 79.55

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Solution

The fourth proportional to 86.99, 130.96 and 79.55 is: 119.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.99 : 130.96 = 79.55 : x
  2. Step 2: Convert to fraction form
    86.99/130.96 = 79.55/x
  3. Step 3: Cross multiply
    86.99x = 130.96 × 79.55
  4. Step 4: Simplify right side
    86.99x = 10,417.87
  5. Step 5: Solve for x
    x = 10,417.87/86.99
  6. Step 6: Final answer
    x = 119.76

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.