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Finding the Fourth Proportional to 97.20, 145.08 and 91.80

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Solution

The fourth proportional to 97.20, 145.08 and 91.80 is: 137.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    97.20 : 145.08 = 91.80 : x
  2. Step 2: Convert to fraction form
    97.20/145.08 = 91.80/x
  3. Step 3: Cross multiply
    97.20x = 145.08 × 91.80
  4. Step 4: Simplify right side
    97.20x = 13,318.34
  5. Step 5: Solve for x
    x = 13,318.34/97.20
  6. Step 6: Final answer
    x = 137.02

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.