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Finding the Fourth Proportional to 829.40, 1,241.40 and 645.80

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Solution

The fourth proportional to 829.40, 1,241.40 and 645.80 is: 966.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    829.40 : 1,241.40 = 645.80 : x
  2. Step 2: Convert to fraction form
    829.40/1,241.40 = 645.80/x
  3. Step 3: Cross multiply
    829.40x = 1,241.40 × 645.80
  4. Step 4: Simplify right side
    829.40x = 801,696.12
  5. Step 5: Solve for x
    x = 801,696.12/829.40
  6. Step 6: Final answer
    x = 966.60

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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.