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Finding the Fourth Proportional to 61.30, 91.80 and 40.90

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Solution

The fourth proportional to 61.30, 91.80 and 40.90 is: 61.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.30 : 91.80 = 40.90 : x
  2. Step 2: Convert to fraction form
    61.30/91.80 = 40.90/x
  3. Step 3: Cross multiply
    61.30x = 91.80 × 40.90
  4. Step 4: Simplify right side
    61.30x = 3,754.62
  5. Step 5: Solve for x
    x = 3,754.62/61.30
  6. Step 6: Final answer
    x = 61.25

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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.