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Finding the Fourth Proportional to 210.59, 315.11 and 128.02

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Solution

The fourth proportional to 210.59, 315.11 and 128.02 is: 191.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.59 : 315.11 = 128.02 : x
  2. Step 2: Convert to fraction form
    210.59/315.11 = 128.02/x
  3. Step 3: Cross multiply
    210.59x = 315.11 × 128.02
  4. Step 4: Simplify right side
    210.59x = 40,339.91
  5. Step 5: Solve for x
    x = 40,339.91/210.59
  6. Step 6: Final answer
    x = 191.55

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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.