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Finding the Fourth Proportional to 903.66, 1,247.31 and 641.70

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Solution

The fourth proportional to 903.66, 1,247.31 and 641.70 is: 885.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    903.66 : 1,247.31 = 641.70 : x
  2. Step 2: Convert to fraction form
    903.66/1,247.31 = 641.70/x
  3. Step 3: Cross multiply
    903.66x = 1,247.31 × 641.70
  4. Step 4: Simplify right side
    903.66x = 800,398.83
  5. Step 5: Solve for x
    x = 800,398.83/903.66
  6. Step 6: Final answer
    x = 885.73

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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.