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Finding the Fourth Proportional to 812.40, 1,121.12 and 463.20

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Solution

The fourth proportional to 812.40, 1,121.12 and 463.20 is: 639.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.40 : 1,121.12 = 463.20 : x
  2. Step 2: Convert to fraction form
    812.40/1,121.12 = 463.20/x
  3. Step 3: Cross multiply
    812.40x = 1,121.12 × 463.20
  4. Step 4: Simplify right side
    812.40x = 519,302.78
  5. Step 5: Solve for x
    x = 519,302.78/812.40
  6. Step 6: Final answer
    x = 639.22

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.