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Finding the Fourth Proportional to 211.20, 291.28 and 172.32

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Solution

The fourth proportional to 211.20, 291.28 and 172.32 is: 237.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.20 : 291.28 = 172.32 : x
  2. Step 2: Convert to fraction form
    211.20/291.28 = 172.32/x
  3. Step 3: Cross multiply
    211.20x = 291.28 × 172.32
  4. Step 4: Simplify right side
    211.20x = 50,193.37
  5. Step 5: Solve for x
    x = 50,193.37/211.20
  6. Step 6: Final answer
    x = 237.66

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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.