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Finding the Fourth Proportional to 847.80, 1,256.04 and 815.40

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Solution

The fourth proportional to 847.80, 1,256.04 and 815.40 is: 1,208.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    847.80 : 1,256.04 = 815.40 : x
  2. Step 2: Convert to fraction form
    847.80/1,256.04 = 815.40/x
  3. Step 3: Cross multiply
    847.80x = 1,256.04 × 815.40
  4. Step 4: Simplify right side
    847.80x = 1,024,175.02
  5. Step 5: Solve for x
    x = 1,024,175.02/847.80
  6. Step 6: Final answer
    x = 1,208.04

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Why These Related Problems?

These problems maintain the same ratio (1.48) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.