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Finding the Fourth Proportional to 1,078.90, 1,488.66 and 636.50

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Solution

The fourth proportional to 1,078.90, 1,488.66 and 636.50 is: 878.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,078.90 : 1,488.66 = 636.50 : x
  2. Step 2: Convert to fraction form
    1,078.90/1,488.66 = 636.50/x
  3. Step 3: Cross multiply
    1,078.90x = 1,488.66 × 636.50
  4. Step 4: Simplify right side
    1,078.90x = 947,532.09
  5. Step 5: Solve for x
    x = 947,532.09/1,078.90
  6. Step 6: Final answer
    x = 878.24

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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.