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Finding the Fourth Proportional to 1,287.18, 1,776.06 and 815.04

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Solution

The fourth proportional to 1,287.18, 1,776.06 and 815.04 is: 1,124.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.18 : 1,776.06 = 815.04 : x
  2. Step 2: Convert to fraction form
    1,287.18/1,776.06 = 815.04/x
  3. Step 3: Cross multiply
    1,287.18x = 1,776.06 × 815.04
  4. Step 4: Simplify right side
    1,287.18x = 1,447,559.94
  5. Step 5: Solve for x
    x = 1,447,559.94/1,287.18
  6. Step 6: Final answer
    x = 1,124.60

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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.