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Finding the Fourth Proportional to 691.09, 949.16 and 640.36

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Solution

The fourth proportional to 691.09, 949.16 and 640.36 is: 879.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.09 : 949.16 = 640.36 : x
  2. Step 2: Convert to fraction form
    691.09/949.16 = 640.36/x
  3. Step 3: Cross multiply
    691.09x = 949.16 × 640.36
  4. Step 4: Simplify right side
    691.09x = 607,800.92
  5. Step 5: Solve for x
    x = 607,800.92/691.09
  6. Step 6: Final answer
    x = 879.48

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.