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Finding the Fourth Proportional to 91.65, 126.39 and 70.90

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Solution

The fourth proportional to 91.65, 126.39 and 70.90 is: 97.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.65 : 126.39 = 70.90 : x
  2. Step 2: Convert to fraction form
    91.65/126.39 = 70.90/x
  3. Step 3: Cross multiply
    91.65x = 126.39 × 70.90
  4. Step 4: Simplify right side
    91.65x = 8,960.42
  5. Step 5: Solve for x
    x = 8,960.42/91.65
  6. Step 6: Final answer
    x = 97.77

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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.