Home / 1,287.20-1,930.80-313.30

Finding the Fourth Proportional to 1,287.20, 1,930.80 and 313.30

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Solution

The fourth proportional to 1,287.20, 1,930.80 and 313.30 is: 469.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.20 : 1,930.80 = 313.30 : x
  2. Step 2: Convert to fraction form
    1,287.20/1,930.80 = 313.30/x
  3. Step 3: Cross multiply
    1,287.20x = 1,930.80 × 313.30
  4. Step 4: Simplify right side
    1,287.20x = 604,919.64
  5. Step 5: Solve for x
    x = 604,919.64/1,287.20
  6. Step 6: Final answer
    x = 469.95

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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.