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Finding the Fourth Proportional to 1,278.65, 1,919.77 and 654.39

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Solution

The fourth proportional to 1,278.65, 1,919.77 and 654.39 is: 982.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.65 : 1,919.77 = 654.39 : x
  2. Step 2: Convert to fraction form
    1,278.65/1,919.77 = 654.39/x
  3. Step 3: Cross multiply
    1,278.65x = 1,919.77 × 654.39
  4. Step 4: Simplify right side
    1,278.65x = 1,256,287.13
  5. Step 5: Solve for x
    x = 1,256,287.13/1,278.65
  6. Step 6: Final answer
    x = 982.51

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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.