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Finding the Fourth Proportional to 1,280.28, 1,920.41 and 816.91

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Solution

The fourth proportional to 1,280.28, 1,920.41 and 816.91 is: 1,225.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.28 : 1,920.41 = 816.91 : x
  2. Step 2: Convert to fraction form
    1,280.28/1,920.41 = 816.91/x
  3. Step 3: Cross multiply
    1,280.28x = 1,920.41 × 816.91
  4. Step 4: Simplify right side
    1,280.28x = 1,568,792.53
  5. Step 5: Solve for x
    x = 1,568,792.53/1,280.28
  6. Step 6: Final answer
    x = 1,225.35

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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.