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Finding the Fourth Proportional to 280.38, 420.70 and 172.10

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Solution

The fourth proportional to 280.38, 420.70 and 172.10 is: 258.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.38 : 420.70 = 172.10 : x
  2. Step 2: Convert to fraction form
    280.38/420.70 = 172.10/x
  3. Step 3: Cross multiply
    280.38x = 420.70 × 172.10
  4. Step 4: Simplify right side
    280.38x = 72,402.47
  5. Step 5: Solve for x
    x = 72,402.47/280.38
  6. Step 6: Final answer
    x = 258.23

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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.