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Finding the Fourth Proportional to 61.80, 91.98 and 61.20

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Solution

The fourth proportional to 61.80, 91.98 and 61.20 is: 91.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.80 : 91.98 = 61.20 : x
  2. Step 2: Convert to fraction form
    61.80/91.98 = 61.20/x
  3. Step 3: Cross multiply
    61.80x = 91.98 × 61.20
  4. Step 4: Simplify right side
    61.80x = 5,629.18
  5. Step 5: Solve for x
    x = 5,629.18/61.80
  6. Step 6: Final answer
    x = 91.09

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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.