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Finding the Fourth Proportional to 280.57, 386.99 and 257.33

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Solution

The fourth proportional to 280.57, 386.99 and 257.33 is: 354.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.57 : 386.99 = 257.33 : x
  2. Step 2: Convert to fraction form
    280.57/386.99 = 257.33/x
  3. Step 3: Cross multiply
    280.57x = 386.99 × 257.33
  4. Step 4: Simplify right side
    280.57x = 99,586.23
  5. Step 5: Solve for x
    x = 99,586.23/280.57
  6. Step 6: Final answer
    x = 354.94

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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.