Home / 1,405.28-2,107.84-431.30

Finding the Fourth Proportional to 1,405.28, 2,107.84 and 431.30

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Solution

The fourth proportional to 1,405.28, 2,107.84 and 431.30 is: 646.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,405.28 : 2,107.84 = 431.30 : x
  2. Step 2: Convert to fraction form
    1,405.28/2,107.84 = 431.30/x
  3. Step 3: Cross multiply
    1,405.28x = 2,107.84 × 431.30
  4. Step 4: Simplify right side
    1,405.28x = 909,111.39
  5. Step 5: Solve for x
    x = 909,111.39/1,405.28
  6. Step 6: Final answer
    x = 646.93

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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.