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Finding the Fourth Proportional to 78.93, 117.75 and 66.18

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Solution

The fourth proportional to 78.93, 117.75 and 66.18 is: 98.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.93 : 117.75 = 66.18 : x
  2. Step 2: Convert to fraction form
    78.93/117.75 = 66.18/x
  3. Step 3: Cross multiply
    78.93x = 117.75 × 66.18
  4. Step 4: Simplify right side
    78.93x = 7,791.78
  5. Step 5: Solve for x
    x = 7,791.78/78.93
  6. Step 6: Final answer
    x = 98.72

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.