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Finding the Fourth Proportional to 1,421.78, 2,128.82 and 804.56

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Solution

The fourth proportional to 1,421.78, 2,128.82 and 804.56 is: 1,204.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.78 : 2,128.82 = 804.56 : x
  2. Step 2: Convert to fraction form
    1,421.78/2,128.82 = 804.56/x
  3. Step 3: Cross multiply
    1,421.78x = 2,128.82 × 804.56
  4. Step 4: Simplify right side
    1,421.78x = 1,712,748.75
  5. Step 5: Solve for x
    x = 1,712,748.75/1,421.78
  6. Step 6: Final answer
    x = 1,204.66

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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.