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Finding the Fourth Proportional to 202.08, 278.64 and 128.30

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Solution

The fourth proportional to 202.08, 278.64 and 128.30 is: 176.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    202.08 : 278.64 = 128.30 : x
  2. Step 2: Convert to fraction form
    202.08/278.64 = 128.30/x
  3. Step 3: Cross multiply
    202.08x = 278.64 × 128.30
  4. Step 4: Simplify right side
    202.08x = 35,748.12
  5. Step 5: Solve for x
    x = 35,748.12/202.08
  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.