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Finding the Fourth Proportional to 91.30, 137.56 and 79.15

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Solution

The fourth proportional to 91.30, 137.56 and 79.15 is: 119.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.30 : 137.56 = 79.15 : x
  2. Step 2: Convert to fraction form
    91.30/137.56 = 79.15/x
  3. Step 3: Cross multiply
    91.30x = 137.56 × 79.15
  4. Step 4: Simplify right side
    91.30x = 10,887.87
  5. Step 5: Solve for x
    x = 10,887.87/91.30
  6. Step 6: Final answer
    x = 119.25

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.