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Finding the Fourth Proportional to 686.88, 948.42 and 438.66

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Solution

The fourth proportional to 686.88, 948.42 and 438.66 is: 605.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.88 : 948.42 = 438.66 : x
  2. Step 2: Convert to fraction form
    686.88/948.42 = 438.66/x
  3. Step 3: Cross multiply
    686.88x = 948.42 × 438.66
  4. Step 4: Simplify right side
    686.88x = 416,033.92
  5. Step 5: Solve for x
    x = 416,033.92/686.88
  6. Step 6: Final answer
    x = 605.69

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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.