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Finding the Fourth Proportional to 431.65, 644.14 and 385.50

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Solution

The fourth proportional to 431.65, 644.14 and 385.50 is: 575.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.65 : 644.14 = 385.50 : x
  2. Step 2: Convert to fraction form
    431.65/644.14 = 385.50/x
  3. Step 3: Cross multiply
    431.65x = 644.14 × 385.50
  4. Step 4: Simplify right side
    431.65x = 248,316.70
  5. Step 5: Solve for x
    x = 248,316.70/431.65
  6. Step 6: Final answer
    x = 575.27

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.