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Finding the Fourth Proportional to 78.07, 117.09 and 74.13

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Solution

The fourth proportional to 78.07, 117.09 and 74.13 is: 111.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.07 : 117.09 = 74.13 : x
  2. Step 2: Convert to fraction form
    78.07/117.09 = 74.13/x
  3. Step 3: Cross multiply
    78.07x = 117.09 × 74.13
  4. Step 4: Simplify right side
    78.07x = 8,679.88
  5. Step 5: Solve for x
    x = 8,679.88/78.07
  6. Step 6: Final answer
    x = 111.18

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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.