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Finding the Fourth Proportional to 5,428, 8,142.32 and 1,780

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Solution

The fourth proportional to 5,428, 8,142.32 and 1,780 is: 2,670.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    5,428 : 8,142.32 = 1,780 : x
  2. Step 2: Convert to fraction form
    5,428/8,142.32 = 1,780/x
  3. Step 3: Cross multiply
    5,428x = 8,142.32 × 1,780
  4. Step 4: Simplify right side
    5,428x = 14,493,329.60
  5. Step 5: Solve for x
    x = 14,493,329.60/5,428
  6. Step 6: Final answer
    x = 2,670.10

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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.