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Finding the Fourth Proportional to 641.39, 885.67 and 420.26

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Solution

The fourth proportional to 641.39, 885.67 and 420.26 is: 580.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.39 : 885.67 = 420.26 : x
  2. Step 2: Convert to fraction form
    641.39/885.67 = 420.26/x
  3. Step 3: Cross multiply
    641.39x = 885.67 × 420.26
  4. Step 4: Simplify right side
    641.39x = 372,206.20
  5. Step 5: Solve for x
    x = 372,206.20/641.39
  6. Step 6: Final answer
    x = 580.32

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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.