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Finding the Fourth Proportional to 210.79, 316.21 and 172.61

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Solution

The fourth proportional to 210.79, 316.21 and 172.61 is: 258.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.79 : 316.21 = 172.61 : x
  2. Step 2: Convert to fraction form
    210.79/316.21 = 172.61/x
  3. Step 3: Cross multiply
    210.79x = 316.21 × 172.61
  4. Step 4: Simplify right side
    210.79x = 54,581.01
  5. Step 5: Solve for x
    x = 54,581.01/210.79
  6. Step 6: Final answer
    x = 258.94

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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.