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Finding the Fourth Proportional to 862.23, 1,291.17 and 428.25

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Solution

The fourth proportional to 862.23, 1,291.17 and 428.25 is: 641.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.23 : 1,291.17 = 428.25 : x
  2. Step 2: Convert to fraction form
    862.23/1,291.17 = 428.25/x
  3. Step 3: Cross multiply
    862.23x = 1,291.17 × 428.25
  4. Step 4: Simplify right side
    862.23x = 552,943.55
  5. Step 5: Solve for x
    x = 552,943.55/862.23
  6. Step 6: Final answer
    x = 641.29

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.