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Finding the Fourth Proportional to 828.36, 1,143.20 and 455.40

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Solution

The fourth proportional to 828.36, 1,143.20 and 455.40 is: 628.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.36 : 1,143.20 = 455.40 : x
  2. Step 2: Convert to fraction form
    828.36/1,143.20 = 455.40/x
  3. Step 3: Cross multiply
    828.36x = 1,143.20 × 455.40
  4. Step 4: Simplify right side
    828.36x = 520,614.42
  5. Step 5: Solve for x
    x = 520,614.42/828.36
  6. Step 6: Final answer
    x = 628.49

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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.