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Finding the Fourth Proportional to 1,298.31, 1,942.66 and 778.67

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Solution

The fourth proportional to 1,298.31, 1,942.66 and 778.67 is: 1,165.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,298.31 : 1,942.66 = 778.67 : x
  2. Step 2: Convert to fraction form
    1,298.31/1,942.66 = 778.67/x
  3. Step 3: Cross multiply
    1,298.31x = 1,942.66 × 778.67
  4. Step 4: Simplify right side
    1,298.31x = 1,512,689.61
  5. Step 5: Solve for x
    x = 1,512,689.61/1,298.31
  6. Step 6: Final answer
    x = 1,165.13

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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.