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Finding the Fourth Proportional to 1,385, 2,077.60 and 615.50

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Solution

The fourth proportional to 1,385, 2,077.60 and 615.50 is: 923.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,385 : 2,077.60 = 615.50 : x
  2. Step 2: Convert to fraction form
    1,385/2,077.60 = 615.50/x
  3. Step 3: Cross multiply
    1,385x = 2,077.60 × 615.50
  4. Step 4: Simplify right side
    1,385x = 1,278,762.80
  5. Step 5: Solve for x
    x = 1,278,762.80/1,385
  6. Step 6: Final answer
    x = 923.29

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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.