Home / 1,280.50-1,921.50-459.48

Finding the Fourth Proportional to 1,280.50, 1,921.50 and 459.48

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Solution

The fourth proportional to 1,280.50, 1,921.50 and 459.48 is: 689.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.50 : 1,921.50 = 459.48 : x
  2. Step 2: Convert to fraction form
    1,280.50/1,921.50 = 459.48/x
  3. Step 3: Cross multiply
    1,280.50x = 1,921.50 × 459.48
  4. Step 4: Simplify right side
    1,280.50x = 882,890.82
  5. Step 5: Solve for x
    x = 882,890.82/1,280.50
  6. Step 6: Final answer
    x = 689.49

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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.