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Finding the Fourth Proportional to 88.46, 121.79 and 78.99

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Solution

The fourth proportional to 88.46, 121.79 and 78.99 is: 108.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.46 : 121.79 = 78.99 : x
  2. Step 2: Convert to fraction form
    88.46/121.79 = 78.99/x
  3. Step 3: Cross multiply
    88.46x = 121.79 × 78.99
  4. Step 4: Simplify right side
    88.46x = 9,619.80
  5. Step 5: Solve for x
    x = 9,619.80/88.46
  6. Step 6: Final answer
    x = 108.75

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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.