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Finding the Fourth Proportional to 908.78, 1,254.09 and 494.78

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Solution

The fourth proportional to 908.78, 1,254.09 and 494.78 is: 682.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    908.78 : 1,254.09 = 494.78 : x
  2. Step 2: Convert to fraction form
    908.78/1,254.09 = 494.78/x
  3. Step 3: Cross multiply
    908.78x = 1,254.09 × 494.78
  4. Step 4: Simplify right side
    908.78x = 620,498.65
  5. Step 5: Solve for x
    x = 620,498.65/908.78
  6. Step 6: Final answer
    x = 682.78

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1.5x scale

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.