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Finding the Fourth Proportional to 385.63, 531.99 and 280.45

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Solution

The fourth proportional to 385.63, 531.99 and 280.45 is: 386.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.63 : 531.99 = 280.45 : x
  2. Step 2: Convert to fraction form
    385.63/531.99 = 280.45/x
  3. Step 3: Cross multiply
    385.63x = 531.99 × 280.45
  4. Step 4: Simplify right side
    385.63x = 149,196.60
  5. Step 5: Solve for x
    x = 149,196.60/385.63
  6. Step 6: Final answer
    x = 386.89

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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.