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Finding the Fourth Proportional to 210.45, 315.77 and 80.51

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Solution

The fourth proportional to 210.45, 315.77 and 80.51 is: 120.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.45 : 315.77 = 80.51 : x
  2. Step 2: Convert to fraction form
    210.45/315.77 = 80.51/x
  3. Step 3: Cross multiply
    210.45x = 315.77 × 80.51
  4. Step 4: Simplify right side
    210.45x = 25,420.66
  5. Step 5: Solve for x
    x = 25,420.66/210.45
  6. Step 6: Final answer
    x = 120.79

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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.