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Finding the Fourth Proportional to 802.80, 1,206.90 and 642.24

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Solution

The fourth proportional to 802.80, 1,206.90 and 642.24 is: 965.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    802.80 : 1,206.90 = 642.24 : x
  2. Step 2: Convert to fraction form
    802.80/1,206.90 = 642.24/x
  3. Step 3: Cross multiply
    802.80x = 1,206.90 × 642.24
  4. Step 4: Simplify right side
    802.80x = 775,119.46
  5. Step 5: Solve for x
    x = 775,119.46/802.80
  6. Step 6: Final answer
    x = 965.52

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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.