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Finding the Fourth Proportional to 428.76, 643.26 and 185.16

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Solution

The fourth proportional to 428.76, 643.26 and 185.16 is: 277.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.76 : 643.26 = 185.16 : x
  2. Step 2: Convert to fraction form
    428.76/643.26 = 185.16/x
  3. Step 3: Cross multiply
    428.76x = 643.26 × 185.16
  4. Step 4: Simplify right side
    428.76x = 119,106.02
  5. Step 5: Solve for x
    x = 119,106.02/428.76
  6. Step 6: Final answer
    x = 277.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.