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Finding the Fourth Proportional to 407.81, 562.78 and 221.30

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Solution

The fourth proportional to 407.81, 562.78 and 221.30 is: 305.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    407.81 : 562.78 = 221.30 : x
  2. Step 2: Convert to fraction form
    407.81/562.78 = 221.30/x
  3. Step 3: Cross multiply
    407.81x = 562.78 × 221.30
  4. Step 4: Simplify right side
    407.81x = 124,543.21
  5. Step 5: Solve for x
    x = 124,543.21/407.81
  6. Step 6: Final answer
    x = 305.40

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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.