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Finding the Fourth Proportional to 172.80, 257.70 and 165.60

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Solution

The fourth proportional to 172.80, 257.70 and 165.60 is: 246.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.80 : 257.70 = 165.60 : x
  2. Step 2: Convert to fraction form
    172.80/257.70 = 165.60/x
  3. Step 3: Cross multiply
    172.80x = 257.70 × 165.60
  4. Step 4: Simplify right side
    172.80x = 42,675.12
  5. Step 5: Solve for x
    x = 42,675.12/172.80
  6. Step 6: Final answer
    x = 246.96

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.