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Finding the Fourth Proportional to 240.90, 361.38 and 78.60

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Solution

The fourth proportional to 240.90, 361.38 and 78.60 is: 117.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    240.90 : 361.38 = 78.60 : x
  2. Step 2: Convert to fraction form
    240.90/361.38 = 78.60/x
  3. Step 3: Cross multiply
    240.90x = 361.38 × 78.60
  4. Step 4: Simplify right side
    240.90x = 28,404.47
  5. Step 5: Solve for x
    x = 28,404.47/240.90
  6. Step 6: Final answer
    x = 117.91

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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.