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Finding the Fourth Proportional to 783.65, 1,078.97 and 665.38

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Solution

The fourth proportional to 783.65, 1,078.97 and 665.38 is: 916.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.65 : 1,078.97 = 665.38 : x
  2. Step 2: Convert to fraction form
    783.65/1,078.97 = 665.38/x
  3. Step 3: Cross multiply
    783.65x = 1,078.97 × 665.38
  4. Step 4: Simplify right side
    783.65x = 717,919.66
  5. Step 5: Solve for x
    x = 717,919.66/783.65
  6. Step 6: Final answer
    x = 916.13

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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.