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Finding the Fourth Proportional to 687.80, 1,031.48 and 225.50

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Solution

The fourth proportional to 687.80, 1,031.48 and 225.50 is: 338.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.80 : 1,031.48 = 225.50 : x
  2. Step 2: Convert to fraction form
    687.80/1,031.48 = 225.50/x
  3. Step 3: Cross multiply
    687.80x = 1,031.48 × 225.50
  4. Step 4: Simplify right side
    687.80x = 232,598.74
  5. Step 5: Solve for x
    x = 232,598.74/687.80
  6. Step 6: Final answer
    x = 338.18

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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.