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Finding the Fourth Proportional to 804.90, 1,206.19 and 640.58

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Solution

The fourth proportional to 804.90, 1,206.19 and 640.58 is: 959.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    804.90 : 1,206.19 = 640.58 : x
  2. Step 2: Convert to fraction form
    804.90/1,206.19 = 640.58/x
  3. Step 3: Cross multiply
    804.90x = 1,206.19 × 640.58
  4. Step 4: Simplify right side
    804.90x = 772,661.19
  5. Step 5: Solve for x
    x = 772,661.19/804.90
  6. Step 6: Final answer
    x = 959.95

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.