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Finding the Fourth Proportional to 1,270.40, 1,905.60 and 540.80

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Solution

The fourth proportional to 1,270.40, 1,905.60 and 540.80 is: 811.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,270.40 : 1,905.60 = 540.80 : x
  2. Step 2: Convert to fraction form
    1,270.40/1,905.60 = 540.80/x
  3. Step 3: Cross multiply
    1,270.40x = 1,905.60 × 540.80
  4. Step 4: Simplify right side
    1,270.40x = 1,030,548.48
  5. Step 5: Solve for x
    x = 1,030,548.48/1,270.40
  6. Step 6: Final answer
    x = 811.20

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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.