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Finding the Fourth Proportional to 687.79, 1,031.78 and 249.07

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Solution

The fourth proportional to 687.79, 1,031.78 and 249.07 is: 373.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.79 : 1,031.78 = 249.07 : x
  2. Step 2: Convert to fraction form
    687.79/1,031.78 = 249.07/x
  3. Step 3: Cross multiply
    687.79x = 1,031.78 × 249.07
  4. Step 4: Simplify right side
    687.79x = 256,986.07
  5. Step 5: Solve for x
    x = 256,986.07/687.79
  6. Step 6: Final answer
    x = 373.64

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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.