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Finding the Fourth Proportional to 1,280.79, 1,919.66 and 499.86

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Solution

The fourth proportional to 1,280.79, 1,919.66 and 499.86 is: 749.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.79 : 1,919.66 = 499.86 : x
  2. Step 2: Convert to fraction form
    1,280.79/1,919.66 = 499.86/x
  3. Step 3: Cross multiply
    1,280.79x = 1,919.66 × 499.86
  4. Step 4: Simplify right side
    1,280.79x = 959,561.25
  5. Step 5: Solve for x
    x = 959,561.25/1,280.79
  6. Step 6: Final answer
    x = 749.19

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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.