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Finding the Fourth Proportional to 78.01, 117.62 and 66.13

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Solution

The fourth proportional to 78.01, 117.62 and 66.13 is: 99.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.01 : 117.62 = 66.13 : x
  2. Step 2: Convert to fraction form
    78.01/117.62 = 66.13/x
  3. Step 3: Cross multiply
    78.01x = 117.62 × 66.13
  4. Step 4: Simplify right side
    78.01x = 7,778.21
  5. Step 5: Solve for x
    x = 7,778.21/78.01
  6. Step 6: Final answer
    x = 99.71

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.