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Finding the Fourth Proportional to 1,003.80, 1,505.80 and 787

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Solution

The fourth proportional to 1,003.80, 1,505.80 and 787 is: 1,180.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,003.80 : 1,505.80 = 787 : x
  2. Step 2: Convert to fraction form
    1,003.80/1,505.80 = 787/x
  3. Step 3: Cross multiply
    1,003.80x = 1,505.80 × 787
  4. Step 4: Simplify right side
    1,003.80x = 1,185,064.60
  5. Step 5: Solve for x
    x = 1,185,064.60/1,003.80
  6. Step 6: Final answer
    x = 1,180.58

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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.