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Finding the Fourth Proportional to 403.76, 556.80 and 279.20

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Solution

The fourth proportional to 403.76, 556.80 and 279.20 is: 385.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.76 : 556.80 = 279.20 : x
  2. Step 2: Convert to fraction form
    403.76/556.80 = 279.20/x
  3. Step 3: Cross multiply
    403.76x = 556.80 × 279.20
  4. Step 4: Simplify right side
    403.76x = 155,458.56
  5. Step 5: Solve for x
    x = 155,458.56/403.76
  6. Step 6: Final answer
    x = 385.03

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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.