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Finding the Fourth Proportional to 838.80, 1,257.12 and 646.02

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Solution

The fourth proportional to 838.80, 1,257.12 and 646.02 is: 968.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.80 : 1,257.12 = 646.02 : x
  2. Step 2: Convert to fraction form
    838.80/1,257.12 = 646.02/x
  3. Step 3: Cross multiply
    838.80x = 1,257.12 × 646.02
  4. Step 4: Simplify right side
    838.80x = 812,124.66
  5. Step 5: Solve for x
    x = 812,124.66/838.80
  6. Step 6: Final answer
    x = 968.20

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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.