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Finding the Fourth Proportional to 1,285.50, 1,926.90 and 919.20

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Solution

The fourth proportional to 1,285.50, 1,926.90 and 919.20 is: 1,377.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.50 : 1,926.90 = 919.20 : x
  2. Step 2: Convert to fraction form
    1,285.50/1,926.90 = 919.20/x
  3. Step 3: Cross multiply
    1,285.50x = 1,926.90 × 919.20
  4. Step 4: Simplify right side
    1,285.50x = 1,771,206.48
  5. Step 5: Solve for x
    x = 1,771,206.48/1,285.50
  6. Step 6: Final answer
    x = 1,377.83

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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.