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Finding the Fourth Proportional to 172.05, 257.65 and 99.69

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Solution

The fourth proportional to 172.05, 257.65 and 99.69 is: 149.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.05 : 257.65 = 99.69 : x
  2. Step 2: Convert to fraction form
    172.05/257.65 = 99.69/x
  3. Step 3: Cross multiply
    172.05x = 257.65 × 99.69
  4. Step 4: Simplify right side
    172.05x = 25,685.13
  5. Step 5: Solve for x
    x = 25,685.13/172.05
  6. Step 6: Final answer
    x = 149.29

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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.