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Finding the Fourth Proportional to 281.38, 421.80 and 137.20

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Solution

The fourth proportional to 281.38, 421.80 and 137.20 is: 205.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    281.38 : 421.80 = 137.20 : x
  2. Step 2: Convert to fraction form
    281.38/421.80 = 137.20/x
  3. Step 3: Cross multiply
    281.38x = 421.80 × 137.20
  4. Step 4: Simplify right side
    281.38x = 57,870.96
  5. Step 5: Solve for x
    x = 57,870.96/281.38
  6. Step 6: Final answer
    x = 205.67

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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.