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Finding the Fourth Proportional to 1,421.55, 2,134.32 and 728.71

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Solution

The fourth proportional to 1,421.55, 2,134.32 and 728.71 is: 1,094.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.55 : 2,134.32 = 728.71 : x
  2. Step 2: Convert to fraction form
    1,421.55/2,134.32 = 728.71/x
  3. Step 3: Cross multiply
    1,421.55x = 2,134.32 × 728.71
  4. Step 4: Simplify right side
    1,421.55x = 1,555,304.26
  5. Step 5: Solve for x
    x = 1,555,304.26/1,421.55
  6. Step 6: Final answer
    x = 1,094.09

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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.