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Finding the Fourth Proportional to 88.58, 121.92 and 79.80

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Solution

The fourth proportional to 88.58, 121.92 and 79.80 is: 109.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.58 : 121.92 = 79.80 : x
  2. Step 2: Convert to fraction form
    88.58/121.92 = 79.80/x
  3. Step 3: Cross multiply
    88.58x = 121.92 × 79.80
  4. Step 4: Simplify right side
    88.58x = 9,729.22
  5. Step 5: Solve for x
    x = 9,729.22/88.58
  6. Step 6: Final answer
    x = 109.84

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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.