Home / 1,678.12-2,315.64-931.90

Finding the Fourth Proportional to 1,678.12, 2,315.64 and 931.90

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Solution

The fourth proportional to 1,678.12, 2,315.64 and 931.90 is: 1,285.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,678.12 : 2,315.64 = 931.90 : x
  2. Step 2: Convert to fraction form
    1,678.12/2,315.64 = 931.90/x
  3. Step 3: Cross multiply
    1,678.12x = 2,315.64 × 931.90
  4. Step 4: Simplify right side
    1,678.12x = 2,157,944.92
  5. Step 5: Solve for x
    x = 2,157,944.92/1,678.12
  6. Step 6: Final answer
    x = 1,285.93

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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.