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Finding the Fourth Proportional to 890.50, 1,336.10 and 428.26

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Solution

The fourth proportional to 890.50, 1,336.10 and 428.26 is: 642.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.50 : 1,336.10 = 428.26 : x
  2. Step 2: Convert to fraction form
    890.50/1,336.10 = 428.26/x
  3. Step 3: Cross multiply
    890.50x = 1,336.10 × 428.26
  4. Step 4: Simplify right side
    890.50x = 572,196.04
  5. Step 5: Solve for x
    x = 572,196.04/890.50
  6. Step 6: Final answer
    x = 642.56

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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.