Home / 1,316.20-1,815.78-999.40

Finding the Fourth Proportional to 1,316.20, 1,815.78 and 999.40

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Solution

The fourth proportional to 1,316.20, 1,815.78 and 999.40 is: 1,378.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,316.20 : 1,815.78 = 999.40 : x
  2. Step 2: Convert to fraction form
    1,316.20/1,815.78 = 999.40/x
  3. Step 3: Cross multiply
    1,316.20x = 1,815.78 × 999.40
  4. Step 4: Simplify right side
    1,316.20x = 1,814,690.53
  5. Step 5: Solve for x
    x = 1,814,690.53/1,316.20
  6. Step 6: Final answer
    x = 1,378.73

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.