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Finding the Fourth Proportional to 80.90, 111.65 and 48.15

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Solution

The fourth proportional to 80.90, 111.65 and 48.15 is: 66.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.90 : 111.65 = 48.15 : x
  2. Step 2: Convert to fraction form
    80.90/111.65 = 48.15/x
  3. Step 3: Cross multiply
    80.90x = 111.65 × 48.15
  4. Step 4: Simplify right side
    80.90x = 5,376.02
  5. Step 5: Solve for x
    x = 5,376.02/80.90
  6. Step 6: Final answer
    x = 66.45

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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.