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Finding the Fourth Proportional to 78.18, 117.03 and 61.02

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Solution

The fourth proportional to 78.18, 117.03 and 61.02 is: 91.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.18 : 117.03 = 61.02 : x
  2. Step 2: Convert to fraction form
    78.18/117.03 = 61.02/x
  3. Step 3: Cross multiply
    78.18x = 117.03 × 61.02
  4. Step 4: Simplify right side
    78.18x = 7,141.17
  5. Step 5: Solve for x
    x = 7,141.17/78.18
  6. Step 6: Final answer
    x = 91.34

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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.