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Finding the Fourth Proportional to 620.80, 931.20 and 187.90

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Solution

The fourth proportional to 620.80, 931.20 and 187.90 is: 281.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.80 : 931.20 = 187.90 : x
  2. Step 2: Convert to fraction form
    620.80/931.20 = 187.90/x
  3. Step 3: Cross multiply
    620.80x = 931.20 × 187.90
  4. Step 4: Simplify right side
    620.80x = 174,972.48
  5. Step 5: Solve for x
    x = 174,972.48/620.80
  6. Step 6: Final answer
    x = 281.85

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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.