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Finding the Fourth Proportional to 387.19, 534.35 and 221.40

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Solution

The fourth proportional to 387.19, 534.35 and 221.40 is: 305.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.19 : 534.35 = 221.40 : x
  2. Step 2: Convert to fraction form
    387.19/534.35 = 221.40/x
  3. Step 3: Cross multiply
    387.19x = 534.35 × 221.40
  4. Step 4: Simplify right side
    387.19x = 118,302.39
  5. Step 5: Solve for x
    x = 118,302.39/387.19
  6. Step 6: Final answer
    x = 305.54

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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.