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Finding the Fourth Proportional to 783.23, 1,078.40 and 636.35

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Solution

The fourth proportional to 783.23, 1,078.40 and 636.35 is: 876.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.23 : 1,078.40 = 636.35 : x
  2. Step 2: Convert to fraction form
    783.23/1,078.40 = 636.35/x
  3. Step 3: Cross multiply
    783.23x = 1,078.40 × 636.35
  4. Step 4: Simplify right side
    783.23x = 686,236.66
  5. Step 5: Solve for x
    x = 686,236.66/783.23
  6. Step 6: Final answer
    x = 876.16

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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.