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Finding the Fourth Proportional to 1,278.80, 1,762.44 and 905.84

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Solution

The fourth proportional to 1,278.80, 1,762.44 and 905.84 is: 1,248.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.80 : 1,762.44 = 905.84 : x
  2. Step 2: Convert to fraction form
    1,278.80/1,762.44 = 905.84/x
  3. Step 3: Cross multiply
    1,278.80x = 1,762.44 × 905.84
  4. Step 4: Simplify right side
    1,278.80x = 1,596,488.65
  5. Step 5: Solve for x
    x = 1,596,488.65/1,278.80
  6. Step 6: Final answer
    x = 1,248.43

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.