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Finding the Fourth Proportional to 88.19, 121.84 and 78.39

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Solution

The fourth proportional to 88.19, 121.84 and 78.39 is: 108.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.19 : 121.84 = 78.39 : x
  2. Step 2: Convert to fraction form
    88.19/121.84 = 78.39/x
  3. Step 3: Cross multiply
    88.19x = 121.84 × 78.39
  4. Step 4: Simplify right side
    88.19x = 9,550.84
  5. Step 5: Solve for x
    x = 9,550.84/88.19
  6. Step 6: Final answer
    x = 108.30

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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.