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Finding the Fourth Proportional to 3,620, 5,430 and 1,311.50

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Solution

The fourth proportional to 3,620, 5,430 and 1,311.50 is: 1,967.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,620 : 5,430 = 1,311.50 : x
  2. Step 2: Convert to fraction form
    3,620/5,430 = 1,311.50/x
  3. Step 3: Cross multiply
    3,620x = 5,430 × 1,311.50
  4. Step 4: Simplify right side
    3,620x = 7,121,445
  5. Step 5: Solve for x
    x = 7,121,445/3,620
  6. Step 6: Final answer
    x = 1,967.25

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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.