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Finding the Fourth Proportional to 91.04, 125.75 and 78.05

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Solution

The fourth proportional to 91.04, 125.75 and 78.05 is: 107.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.04 : 125.75 = 78.05 : x
  2. Step 2: Convert to fraction form
    91.04/125.75 = 78.05/x
  3. Step 3: Cross multiply
    91.04x = 125.75 × 78.05
  4. Step 4: Simplify right side
    91.04x = 9,815.30
  5. Step 5: Solve for x
    x = 9,815.30/91.04
  6. Step 6: Final answer
    x = 107.82

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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.