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Finding the Fourth Proportional to 202.05, 278.70 and 128.25

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Solution

The fourth proportional to 202.05, 278.70 and 128.25 is: 176.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    202.05 : 278.70 = 128.25 : x
  2. Step 2: Convert to fraction form
    202.05/278.70 = 128.25/x
  3. Step 3: Cross multiply
    202.05x = 278.70 × 128.25
  4. Step 4: Simplify right side
    202.05x = 35,743.28
  5. Step 5: Solve for x
    x = 35,743.28/202.05
  6. Step 6: Final answer
    x = 176.90

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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.