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Finding the Fourth Proportional to 159.39, 239.15 and 78.18

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Solution

The fourth proportional to 159.39, 239.15 and 78.18 is: 117.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.39 : 239.15 = 78.18 : x
  2. Step 2: Convert to fraction form
    159.39/239.15 = 78.18/x
  3. Step 3: Cross multiply
    159.39x = 239.15 × 78.18
  4. Step 4: Simplify right side
    159.39x = 18,696.36
  5. Step 5: Solve for x
    x = 18,696.36/159.39
  6. Step 6: Final answer
    x = 117.30

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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.