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Finding the Fourth Proportional to 210.92, 291.06 and 128.06

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Solution

The fourth proportional to 210.92, 291.06 and 128.06 is: 176.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.92 : 291.06 = 128.06 : x
  2. Step 2: Convert to fraction form
    210.92/291.06 = 128.06/x
  3. Step 3: Cross multiply
    210.92x = 291.06 × 128.06
  4. Step 4: Simplify right side
    210.92x = 37,271.69
  5. Step 5: Solve for x
    x = 37,271.69/210.92
  6. Step 6: Final answer
    x = 176.71

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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.