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Finding the Fourth Proportional to 128.93, 177.86 and 79.77

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Solution

The fourth proportional to 128.93, 177.86 and 79.77 is: 110.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.93 : 177.86 = 79.77 : x
  2. Step 2: Convert to fraction form
    128.93/177.86 = 79.77/x
  3. Step 3: Cross multiply
    128.93x = 177.86 × 79.77
  4. Step 4: Simplify right side
    128.93x = 14,187.76
  5. Step 5: Solve for x
    x = 14,187.76/128.93
  6. Step 6: Final answer
    x = 110.05

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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.