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Finding the Fourth Proportional to 210.49, 315.75 and 80.47

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Solution

The fourth proportional to 210.49, 315.75 and 80.47 is: 120.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.49 : 315.75 = 80.47 : x
  2. Step 2: Convert to fraction form
    210.49/315.75 = 80.47/x
  3. Step 3: Cross multiply
    210.49x = 315.75 × 80.47
  4. Step 4: Simplify right side
    210.49x = 25,408.01
  5. Step 5: Solve for x
    x = 25,408.01/210.49
  6. Step 6: Final answer
    x = 120.71

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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.