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Finding the Fourth Proportional to 86.90, 119.80 and 54.14

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Solution

The fourth proportional to 86.90, 119.80 and 54.14 is: 74.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.90 : 119.80 = 54.14 : x
  2. Step 2: Convert to fraction form
    86.90/119.80 = 54.14/x
  3. Step 3: Cross multiply
    86.90x = 119.80 × 54.14
  4. Step 4: Simplify right side
    86.90x = 6,485.97
  5. Step 5: Solve for x
    x = 6,485.97/86.90
  6. Step 6: Final answer
    x = 74.64

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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.