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Finding the Fourth Proportional to 1,280.49, 1,917.59 and 816.90

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Solution

The fourth proportional to 1,280.49, 1,917.59 and 816.90 is: 1,223.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.49 : 1,917.59 = 816.90 : x
  2. Step 2: Convert to fraction form
    1,280.49/1,917.59 = 816.90/x
  3. Step 3: Cross multiply
    1,280.49x = 1,917.59 × 816.90
  4. Step 4: Simplify right side
    1,280.49x = 1,566,475.19
  5. Step 5: Solve for x
    x = 1,566,475.19/1,280.49
  6. Step 6: Final answer
    x = 1,223.34

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1.5x scale

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.