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Finding the Fourth Proportional to 1,720.28, 2,580.42 and 421.76

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Solution

The fourth proportional to 1,720.28, 2,580.42 and 421.76 is: 632.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,720.28 : 2,580.42 = 421.76 : x
  2. Step 2: Convert to fraction form
    1,720.28/2,580.42 = 421.76/x
  3. Step 3: Cross multiply
    1,720.28x = 2,580.42 × 421.76
  4. Step 4: Simplify right side
    1,720.28x = 1,088,317.94
  5. Step 5: Solve for x
    x = 1,088,317.94/1,720.28
  6. Step 6: Final answer
    x = 632.64

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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.