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Finding the Fourth Proportional to 1,288.80, 1,777.95 and 817.29

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Solution

The fourth proportional to 1,288.80, 1,777.95 and 817.29 is: 1,127.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.80 : 1,777.95 = 817.29 : x
  2. Step 2: Convert to fraction form
    1,288.80/1,777.95 = 817.29/x
  3. Step 3: Cross multiply
    1,288.80x = 1,777.95 × 817.29
  4. Step 4: Simplify right side
    1,288.80x = 1,453,100.76
  5. Step 5: Solve for x
    x = 1,453,100.76/1,288.80
  6. Step 6: Final answer
    x = 1,127.48

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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.