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Finding the Fourth Proportional to 1,942.40, 2,913.64 and 643.88

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Solution

The fourth proportional to 1,942.40, 2,913.64 and 643.88 is: 965.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,942.40 : 2,913.64 = 643.88 : x
  2. Step 2: Convert to fraction form
    1,942.40/2,913.64 = 643.88/x
  3. Step 3: Cross multiply
    1,942.40x = 2,913.64 × 643.88
  4. Step 4: Simplify right side
    1,942.40x = 1,876,034.52
  5. Step 5: Solve for x
    x = 1,876,034.52/1,942.40
  6. Step 6: Final answer
    x = 965.83

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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.