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Finding the Fourth Proportional to 687.78, 949.41 and 455.46

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Solution

The fourth proportional to 687.78, 949.41 and 455.46 is: 628.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.78 : 949.41 = 455.46 : x
  2. Step 2: Convert to fraction form
    687.78/949.41 = 455.46/x
  3. Step 3: Cross multiply
    687.78x = 949.41 × 455.46
  4. Step 4: Simplify right side
    687.78x = 432,418.28
  5. Step 5: Solve for x
    x = 432,418.28/687.78
  6. Step 6: Final answer
    x = 628.72

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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.