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Finding the Fourth Proportional to 641.70, 885.20 and 389.46

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Solution

The fourth proportional to 641.70, 885.20 and 389.46 is: 537.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.70 : 885.20 = 389.46 : x
  2. Step 2: Convert to fraction form
    641.70/885.20 = 389.46/x
  3. Step 3: Cross multiply
    641.70x = 885.20 × 389.46
  4. Step 4: Simplify right side
    641.70x = 344,748.04
  5. Step 5: Solve for x
    x = 344,748.04/641.70
  6. Step 6: Final answer
    x = 537.24

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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.