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Finding the Fourth Proportional to 286.58, 429.91 and 78.39

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Solution

The fourth proportional to 286.58, 429.91 and 78.39 is: 117.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.58 : 429.91 = 78.39 : x
  2. Step 2: Convert to fraction form
    286.58/429.91 = 78.39/x
  3. Step 3: Cross multiply
    286.58x = 429.91 × 78.39
  4. Step 4: Simplify right side
    286.58x = 33,700.45
  5. Step 5: Solve for x
    x = 33,700.45/286.58
  6. Step 6: Final answer
    x = 117.59

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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.