Home / 1,420.69-2,131.32-689.86

Finding the Fourth Proportional to 1,420.69, 2,131.32 and 689.86

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Solution

The fourth proportional to 1,420.69, 2,131.32 and 689.86 is: 1,034.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,420.69 : 2,131.32 = 689.86 : x
  2. Step 2: Convert to fraction form
    1,420.69/2,131.32 = 689.86/x
  3. Step 3: Cross multiply
    1,420.69x = 2,131.32 × 689.86
  4. Step 4: Simplify right side
    1,420.69x = 1,470,312.42
  5. Step 5: Solve for x
    x = 1,470,312.42/1,420.69
  6. Step 6: Final answer
    x = 1,034.93

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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.