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Finding the Fourth Proportional to 155.90, 233.90 and 78.78

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Solution

The fourth proportional to 155.90, 233.90 and 78.78 is: 118.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.90 : 233.90 = 78.78 : x
  2. Step 2: Convert to fraction form
    155.90/233.90 = 78.78/x
  3. Step 3: Cross multiply
    155.90x = 233.90 × 78.78
  4. Step 4: Simplify right side
    155.90x = 18,426.64
  5. Step 5: Solve for x
    x = 18,426.64/155.90
  6. Step 6: Final answer
    x = 118.20

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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.