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Finding the Fourth Proportional to 824.64, 1,139.04 and 678.84

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Solution

The fourth proportional to 824.64, 1,139.04 and 678.84 is: 937.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    824.64 : 1,139.04 = 678.84 : x
  2. Step 2: Convert to fraction form
    824.64/1,139.04 = 678.84/x
  3. Step 3: Cross multiply
    824.64x = 1,139.04 × 678.84
  4. Step 4: Simplify right side
    824.64x = 773,225.91
  5. Step 5: Solve for x
    x = 773,225.91/824.64
  6. Step 6: Final answer
    x = 937.65

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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.