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Finding the Fourth Proportional to 428.91, 642.88 and 185.23

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Solution

The fourth proportional to 428.91, 642.88 and 185.23 is: 277.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.91 : 642.88 = 185.23 : x
  2. Step 2: Convert to fraction form
    428.91/642.88 = 185.23/x
  3. Step 3: Cross multiply
    428.91x = 642.88 × 185.23
  4. Step 4: Simplify right side
    428.91x = 119,080.66
  5. Step 5: Solve for x
    x = 119,080.66/428.91
  6. Step 6: Final answer
    x = 277.64

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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.