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Finding the Fourth Proportional to 609.90, 841.38 and 388.80

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Solution

The fourth proportional to 609.90, 841.38 and 388.80 is: 536.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.90 : 841.38 = 388.80 : x
  2. Step 2: Convert to fraction form
    609.90/841.38 = 388.80/x
  3. Step 3: Cross multiply
    609.90x = 841.38 × 388.80
  4. Step 4: Simplify right side
    609.90x = 327,128.54
  5. Step 5: Solve for x
    x = 327,128.54/609.90
  6. Step 6: Final answer
    x = 536.36

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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.