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Finding the Fourth Proportional to 280.84, 420.63 and 172.39

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Solution

The fourth proportional to 280.84, 420.63 and 172.39 is: 258.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.84 : 420.63 = 172.39 : x
  2. Step 2: Convert to fraction form
    280.84/420.63 = 172.39/x
  3. Step 3: Cross multiply
    280.84x = 420.63 × 172.39
  4. Step 4: Simplify right side
    280.84x = 72,512.41
  5. Step 5: Solve for x
    x = 72,512.41/280.84
  6. Step 6: Final answer
    x = 258.20

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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.