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Finding the Fourth Proportional to 187.80, 281.78 and 90.30

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Solution

The fourth proportional to 187.80, 281.78 and 90.30 is: 135.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.80 : 281.78 = 90.30 : x
  2. Step 2: Convert to fraction form
    187.80/281.78 = 90.30/x
  3. Step 3: Cross multiply
    187.80x = 281.78 × 90.30
  4. Step 4: Simplify right side
    187.80x = 25,444.73
  5. Step 5: Solve for x
    x = 25,444.73/187.80
  6. Step 6: Final answer
    x = 135.49

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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.