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Finding the Fourth Proportional to 280.80, 387.45 and 170.31

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Solution

The fourth proportional to 280.80, 387.45 and 170.31 is: 235.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.80 : 387.45 = 170.31 : x
  2. Step 2: Convert to fraction form
    280.80/387.45 = 170.31/x
  3. Step 3: Cross multiply
    280.80x = 387.45 × 170.31
  4. Step 4: Simplify right side
    280.80x = 65,986.61
  5. Step 5: Solve for x
    x = 65,986.61/280.80
  6. Step 6: Final answer
    x = 235.00

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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.