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Finding the Fourth Proportional to 1,210.40, 1,815.64 and 480

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Solution

The fourth proportional to 1,210.40, 1,815.64 and 480 is: 720.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,210.40 : 1,815.64 = 480 : x
  2. Step 2: Convert to fraction form
    1,210.40/1,815.64 = 480/x
  3. Step 3: Cross multiply
    1,210.40x = 1,815.64 × 480
  4. Step 4: Simplify right side
    1,210.40x = 871,507.20
  5. Step 5: Solve for x
    x = 871,507.20/1,210.40
  6. Step 6: Final answer
    x = 720.02

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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.