Home / 1,390.40-2,082.24-811.52

Finding the Fourth Proportional to 1,390.40, 2,082.24 and 811.52

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Solution

The fourth proportional to 1,390.40, 2,082.24 and 811.52 is: 1,215.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,390.40 : 2,082.24 = 811.52 : x
  2. Step 2: Convert to fraction form
    1,390.40/2,082.24 = 811.52/x
  3. Step 3: Cross multiply
    1,390.40x = 2,082.24 × 811.52
  4. Step 4: Simplify right side
    1,390.40x = 1,689,779.40
  5. Step 5: Solve for x
    x = 1,689,779.40/1,390.40
  6. Step 6: Final answer
    x = 1,215.32

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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.