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Finding the Fourth Proportional to 1,275, 1,908.51 and 813.30

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Solution

The fourth proportional to 1,275, 1,908.51 and 813.30 is: 1,217.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,275 : 1,908.51 = 813.30 : x
  2. Step 2: Convert to fraction form
    1,275/1,908.51 = 813.30/x
  3. Step 3: Cross multiply
    1,275x = 1,908.51 × 813.30
  4. Step 4: Simplify right side
    1,275x = 1,552,191.18
  5. Step 5: Solve for x
    x = 1,552,191.18/1,275
  6. Step 6: Final answer
    x = 1,217.40

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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.