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Finding the Fourth Proportional to 278.49, 384.35 and 172.21

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Solution

The fourth proportional to 278.49, 384.35 and 172.21 is: 237.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.49 : 384.35 = 172.21 : x
  2. Step 2: Convert to fraction form
    278.49/384.35 = 172.21/x
  3. Step 3: Cross multiply
    278.49x = 384.35 × 172.21
  4. Step 4: Simplify right side
    278.49x = 66,188.91
  5. Step 5: Solve for x
    x = 66,188.91/278.49
  6. Step 6: Final answer
    x = 237.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.