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Finding the Fourth Proportional to 398.28, 549.68 and 380.76

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Solution

The fourth proportional to 398.28, 549.68 and 380.76 is: 525.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.28 : 549.68 = 380.76 : x
  2. Step 2: Convert to fraction form
    398.28/549.68 = 380.76/x
  3. Step 3: Cross multiply
    398.28x = 549.68 × 380.76
  4. Step 4: Simplify right side
    398.28x = 209,296.16
  5. Step 5: Solve for x
    x = 209,296.16/398.28
  6. Step 6: Final answer
    x = 525.50

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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.