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Finding the Fourth Proportional to 91.70, 137.48 and 78.08

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Solution

The fourth proportional to 91.70, 137.48 and 78.08 is: 117.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.70 : 137.48 = 78.08 : x
  2. Step 2: Convert to fraction form
    91.70/137.48 = 78.08/x
  3. Step 3: Cross multiply
    91.70x = 137.48 × 78.08
  4. Step 4: Simplify right side
    91.70x = 10,733.36
  5. Step 5: Solve for x
    x = 10,733.36/91.70
  6. Step 6: Final answer
    x = 117.06

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.