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Finding the Fourth Proportional to 398.28, 549.64 and 221.27

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Solution

The fourth proportional to 398.28, 549.64 and 221.27 is: 305.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.28 : 549.64 = 221.27 : x
  2. Step 2: Convert to fraction form
    398.28/549.64 = 221.27/x
  3. Step 3: Cross multiply
    398.28x = 549.64 × 221.27
  4. Step 4: Simplify right side
    398.28x = 121,615.13
  5. Step 5: Solve for x
    x = 121,615.13/398.28
  6. Step 6: Final answer
    x = 305.35

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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.