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Finding the Fourth Proportional to 812.99, 1,219.95 and 380.18

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Solution

The fourth proportional to 812.99, 1,219.95 and 380.18 is: 570.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.99 : 1,219.95 = 380.18 : x
  2. Step 2: Convert to fraction form
    812.99/1,219.95 = 380.18/x
  3. Step 3: Cross multiply
    812.99x = 1,219.95 × 380.18
  4. Step 4: Simplify right side
    812.99x = 463,794.49
  5. Step 5: Solve for x
    x = 463,794.49/812.99
  6. Step 6: Final answer
    x = 570.48

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Double scale
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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.