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Finding the Fourth Proportional to 1,288.45, 1,778.09 and 764.79

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Solution

The fourth proportional to 1,288.45, 1,778.09 and 764.79 is: 1,055.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.45 : 1,778.09 = 764.79 : x
  2. Step 2: Convert to fraction form
    1,288.45/1,778.09 = 764.79/x
  3. Step 3: Cross multiply
    1,288.45x = 1,778.09 × 764.79
  4. Step 4: Simplify right side
    1,288.45x = 1,359,860.05
  5. Step 5: Solve for x
    x = 1,359,860.05/1,288.45
  6. Step 6: Final answer
    x = 1,055.42

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1.5x scale

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.