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Finding the Fourth Proportional to 421.35, 581.15 and 281.40

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Solution

The fourth proportional to 421.35, 581.15 and 281.40 is: 388.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.35 : 581.15 = 281.40 : x
  2. Step 2: Convert to fraction form
    421.35/581.15 = 281.40/x
  3. Step 3: Cross multiply
    421.35x = 581.15 × 281.40
  4. Step 4: Simplify right side
    421.35x = 163,534.20
  5. Step 5: Solve for x
    x = 163,534.20/421.35
  6. Step 6: Final answer
    x = 388.12

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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.